Ultrasound assembly for use with light activated drugs

ABSTRACT

A kit and method for causing tissue death within a tissue site is disclosed. The kit includes a media with a light activated drug activatable upon exposure to a particular level of ultrasound energy. The kit also includes a catheter with a lumen coupled with a media delivery port through which the light activated drug can be locally delivered to the tissue site. The ultrasound transducer is configured to transmit the level of ultrasound energy which activates the light activated drug with sufficient power that the ultrasound energy can penetrate the tissue site.

RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No.09/158,316, entitled Ultrasound Assembly for Use With Light ActivatedDrugs, filed Sep. 21, 1998 now U.S. Pat. No. 6,176,842, which is aContinuation-In-Part of U.S. application Ser. No. 08/972,846; filed Nov.18, 1997, now abandoned; entitled Ultrasound Therapy Device which is aContinuation of U.S. application Ser. No. 08/611,105; filed Mar. 5,1996, now abandoned; entitled Ultrasound Therapy Device which claimspriority to Japanese application number P07-048710; filed Mar. 8, 1995.This application is also a Continuation-In-Part of U.S. application Ser.No. 09/129,980, now U.S. Pat. No. 6,210,356; Aug. 5, 1998, and entitledUltrasound Assembly for Use With a Catheter. This application is also aContinuation-In-Part of Japanese application number J970617JS0; filedSep. 19, 1997; entitled Drug Carrier and Method of Using Same.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and catheter for treatingbiological tissues with light activated drugs, and more particularly, toa method and catheter for treating biological tissues by delivering alight activated drug to a biological tissue and exposing the lightactivated drug to ultrasound energy.

2. Description of Related Art

It is frequently desirable to kill targeted biological tissues such astumors and atheroma. One technique for causing targeted tissue death iscalled photodynamic therapy which requires the use of light activateddrugs. Light activated drugs are inactive until exposed to light ofparticular wavelengths, however, upon exposure to light of theappropriate wavelength activated drugs can exhibit a cytotoxic effect onthe tissues where they are localized. It has been postulated that thecytotoxic effect is a result of the formation of singlet oxygen onexposure to light.

Photodynamic therapy begins with the systemic administration of aselected light activated drug to a patient. At first, the drug dispersesthroughout the body and is taken up by most tissues within the body.After a period of time usually between 3 and 48 hours, the drug clearsfrom most normal tissue and is retained to a greater degree in lipidrich regions such as the liver, kidney, tumor and atheroma. A lightsource, such as a fiber optic, is then directed to a targeted tissuesite which includes the light activated drug. The tissues of the tissuesite are then exposed to light from the light source in order toactivate any light activated drugs within the tissue site. Theactivation of the light activated drug causes tissue death within thetissue site.

Several difficulties can be encountered during photodynamic therapy. Forinstance, since the light activated drug is typically administeredsystemically, the concentration of the light activated drug within thetargeted tissue site is limited by the quantity of light activated drugadministered. The concentration of the light activated drug within atissue site can also be limited by the degree of selective uptake of thelight activated drug into the tissue site. Specifically, if the targetedtissue site does not selectively uptake the light activated drug, theconcentration of light activated drug within the tissue site can be toolow for an effective treatment.

An additional problem associated with photodynamic therapy concernsdepth of treatment. Light cannot penetrate deeply into opaque tissues.As a result, the depth that light penetrates most tissue sites islimited. This limited depth can prevent photodynamic therapy from beingused to treat tissues which are located deeply in the interior of atissue site.

There is currently a need for a method and apparatus which can be usedto cause death to tissues death deep within a tissue site. When themethod and apparatus employ light activated drugs, the method andapparatus should be able to provide an appropriate concentration oflight activated drug within the tissue site.

SUMMARY OF THE INVENTION

An object for an embodiment of the invention is causing tissue deathwithin a tissue site.

Another object for an embodiment of the present invention is locallydelivering a light activated drug to a tissue site and activating thelight activated drug.

Yet another object for an embodiment of the present invention is locallydelivering a light activated drug to a tissue site and deliveringultrasound energy to the delivered light activated drug to activate thelight activated drug.

A further object for an embodiment of the present invention is using acatheter to locally deliver a light activated drug to a tissue site anddelivering ultrasound energy from an ultrasound element on the catheterto activate the light activated drug.

Yet a further object for an embodiment of the present invention isincluding the light activated drug in an emulsion, locally deliveringthe emulsion to a tissue site and delivering ultrasound energy to thelight activated drug within the tissue site to activate the lightactivated drug.

Even a further object for an embodiment of the present invention isincluding the light activated drug in a liposome, locally delivering theliposome to a tissue site and delivering ultrasound energy to the lightactivated drug within the tissue site to activate the light activateddrug.

An additional object for an embodiment of the present invention isincluding the light activated drug in an aqueous solution, locallydelivering the aqueous solution to a tissue site and deliveringultrasound energy to the light activated drug within the tissue site toactivate the light activated drug.

Yet a further object for an embodiment of the present invention isincluding the light activated drug in an emulsion, systemicallydelivering the emulsion, providing the light activated drug sufficienttime to localize within a tissue site and delivering ultrasound energyto the light activated drug within the tissue site to activate the lightactivated drug.

Even a further object for an embodiment of the present invention isincluding the light activated drug in liposomes, systemically deliveringthe liposomes, providing the light activated drug sufficient time tolocalize within a tissue site and delivering ultrasound energy to thelight activated drug within the tissue site to activate the lightactivated drug.

An additional object for an embodiment of the present invention isincluding the light activated drug in an aqueous solution, systemicallydelivering the aqueous solution, providing the light activated drugsufficient time to localize within a tissue site and deliveringultrasound energy to the light activated drug within the tissue site toactivate the light activated drug.

Another object for an embodiment of the present invention is coupling asite directing molecule to a light activated drug, locally deliveringthe light activated drug to a tissue site and activating the lightactivated drug within the tissue site.

Yet another object for an embodiment of the invention is providing acatheter for locally delivering a media including a light activated drugto a tissue site. The catheter including an ultrasound assemblyconfigured to activate the light activated drug within the tissue site.

A further object for an embodiment of the invention is providing acatheter for delivering a media including a light activated drug to atissue site. The catheter including an ultrasound assembly for reducingexposure of the light activated drug to ultrasound energy until thelight activated drug has been delivered from within the catheter.

A kit for causing tissue death within a tissue site is disclosed. Thekit includes a media with a light activated drug activatable uponexposure to a particular level of ultrasound energy. The kit alsoincludes a catheter with a lumen coupled with a media delivery portthrough which the light activated drug can be locally delivered to thetissue site. The ultrasound transducer is configured to transmit thelevel of ultrasound energy which activates the light activated drug withsufficient power that the ultrasound energy can penetrate the tissuesite.

A method for causing tissue death in a subdermal tissue site is alsodisclosed. The method includes providing a catheter for locallydelivering a light activated drug to the subdermal tissue site, thecatheter including an ultrasound transducer. The method also includeslocally delivering the light activated drug to the tissue site;producing ultrasound energy from the ultrasound transducer, anddirecting the ultrasound energy to the subdermal tissue site followingpenetration of the light activated drug into the subdermal tissue siteto activate least a portion of the light activated drug within thesubdermal tissue site.

A method for activating a light activated drug is also disclosed. Themethod includes providing a catheter with an ultrasound transducer. Themethod also includes introducing the light activated drug into apatient's body where a subdermal tissue site absorbs at least a portionof the light activated drug; producing ultrasound energy; directing theultrasound energy to the light activated containing subdermal tissuesite including the light activated drug; and activating at least aportion of the light activated drug in the subdermal selected tissuesite.

A method for releasing a therapeutic from a microbubble is alsodisclosed. The method includes providing a microbubble with a lightactivated drug activatable upon exposure to ultrasound energy; anddelivering ultrasound energy to the microbubble at a frequency andintensity which activates the light activated drug to cause a rupture ofthe microbubble.

A microbubble is also disclosed. The microbubble includes a substratedefining a shell of the microbubble and having a thickness permittinghydraulic transport of the microbubble. The microbubble also includes alight activated drug activatable upon exposure to ultrasound energy.Activation of the light activated drug causes a disruption in the shellsufficient to cause a rupture of the microbubble. The microbubblefurther includes a therapeutic releasable from the microbubble uponrupture of the microbubble and yielding a therapeutic effect uponrelease from the microbubble.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A is a side view of a catheter for locally delivering a mediaincluding a light activated drug to a tissue site.

FIG. 1B is an axial cross section of an ultrasound assembly for use withthe catheter shown in FIG. 1A.

FIG. 1C is a lateral cross section of an ultrasound assembly for usewith the catheter shown in FIG. 1A.

FIG. 2A is a side view of a catheter having an elongated body and anultrasound assembly which is flush with the elongated body.

FIG. 2B is an axial cross section of the ultrasound assembly illustratedin FIG. 2A.

FIG. 2C is a lateral cross section of the ultrasound assemblyillustrated in FIG. 2A.

FIG. 3A illustrates a catheter with a utility lumen and a second utilitylumen.

FIG. 3B is an axial cross section of the ultrasound assembly illustratedin the catheter of FIG. 3A.

FIG. 4A is a side view of a catheter including a plurality of ultrasoundassemblies.

FIG. 4B is a cross section of an ultrasound assembly included on acatheter with a plurality of utility lumens.

FIG. 4C is a cross section of an ultrasound assembly included on acatheter with a plurality of utility lumens.

FIG. 5A is a side view of a catheter including a balloon.

FIG. 5B is a cross section of a catheter with a balloon which include anultrasound assembly.

FIG. 6A is a side view of a catheter with a balloon positioned distallyrelative to an ultrasound assembly.

FIG. 6B is a side view of a catheter with an ultrasound assemblypositioned distally relative to a balloon.

FIG. 6C is a cross section of a catheter with an ultrasound assemblypositioned at the distal end of the catheter.

FIG. 7A is a side view of a catheter with a media delivery portpositioned between an ultrasound assembly and a balloon.

FIG. 7B is a side view of a catheter with an ultrasound assemblypositioned between a media delivery port and a balloon.

FIG. 7C is a cross section of a catheter with an ultrasound assemblypositioned at the distal end of the catheter.

FIG. 8A is a side view of a catheter including a media delivery port andan ultrasound assembly positioned between first and second balloons.

FIG. 8B is a side view of a catheter including a media delivery port andan ultrasound assembly positioned between first and second balloons.

FIG. 8C is a cross section of a balloon included on a catheter having afirst and second balloon.

FIG. 9A illustrates an ultrasound assembly positioned adjacent to atissue site and microbubbles delivered via a utility lumen.

FIG. 9B illustrates an ultrasound assembly positioned adjacent to atissue site and a media delivered via a media delivery port.

FIG. 9C illustrates an ultrasound assembly positioned adjacent to atissue site and a media delivered via a media delivery port while aguidewire is positioned in a utility lumen.

FIG. 9D illustrates a catheter including a balloon positioned adjacentto a tissue site.

FIG. 9E illustrates a catheter including a balloon expanded into contactwith a tissue site.

FIG. 9F illustrates a catheter with an ultrasound assembly outside aballoon positioned at a tissue site.

FIG. 9G illustrates the balloon of FIG. 9F expanded into contact with avessel so as to occlude the vessel.

FIG. 9H illustrates a catheter with an ultrasound assembly outside afirst and second balloon positioned at a tissue site;

FIG. 9I illustrates the first and second balloon of FIG. 9H expandedinto contact with a vessel so as to occlude the vessel.

FIG. 10A is a cross section of an ultrasound assembly according to thepresent invention.

FIG. 10B is a cross section of an ultrasound assembly according to thepresent invention.

FIG. 10C illustrates a support member with integral supports.

FIG. 10D illustrates a support member which is supported by an outercoating.

FIG. 11A is a cross section of an ultrasound assembly including twoconcentric ultrasound transducers in contact with one another.

FIG. 11B is a cross section of an ultrasound assembly including twoseparated and concentric ultrasound transducers.

FIG. 11C is a cross section of an ultrasound assembly including twoultrasound transducers where a chamber is defined between one of theultrasound transducers and an elongated body.

FIG. 11D is a cross section of an ultrasound assembly including twolongitudinally adjacent ultrasound transducers in physical contact withone another.

FIG. 11E is a cross section of an ultrasound assembly including twoseparated and longitudinally adjacent ultrasound transducers.

FIG. 11F is a cross section of an ultrasound assembly including twolongitudinally adjacent ultrasound transducers with a single chamberpositioned between both ultrasound transducers and an elongated body.

FIG. 11G is a cross section of an ultrasound assembly including twolongitudinally adjacent ultrasound transducers with different chamberspositioned between each ultrasound transducers and an elongated body.

FIG. 11H is a cross section of an ultrasound assembly including twolongitudinally adjacent ultrasound transducers in contact with oneanother and having a single chamber positioned between each ultrasoundtransducers and an elongated body.

FIG. 12A is a cross section of a catheter which includes an ultrasoundassembly module which is independent of a first catheter component and asecond catheter component.

FIG. 12B illustrates the first and second catheter components coupledwith the ultrasound assembly module.

FIG. 12C is a cross section of an ultrasound assembly which is integralwith a catheter.

FIG. 13A is a cross section of an ultrasound assembly configured toradiate ultrasound energy in a radial direction. The lines which drivethe ultrasound transducer pass through a utility lumen in the catheter.

FIG. 13B is a cross section of an ultrasound assembly configured toradiate ultrasound energy in a radial direction. The lines which drivethe ultrasound transducer pass through line lumens in the catheter.

FIG. 13C is a cross section of an ultrasound assembly configured tolongitudinally radiate ultrasound energy. The distal portion of one linetravels proximally through the outer coating.

FIG. 13D is a cross section of an ultrasound assembly configured tolongitudinally transmit ultrasound energy. The distal portion of oneline travels proximally through a line lumen in the catheter.

FIG. 14A illustrates ultrasound transducers connected in parallel.

FIG. 14B illustrates ultrasound transducers connected in series.

FIG. 14C illustrates ultrasound transducers connected with a commonline.

FIG. 15 illustrates a circuit for electrically coupling temperaturesensors.

FIG. 16 illustrates a feedback control system for use with a catheterincluding an ultrasound assembly

FIGS. 17A-N illustrate pyrrole-based macrocyclic classes of lightemitting drugs.

FIG. 17B-2 illustrates possible texaphyrin derivation sites.

FIGS. 18A-F illustrate the formula of preferred light emitting drugs foruse with media including microbubbles.

FIG. 19 illustrates a formula for a porphyrin group.

FIGS. 20A-D illustrate the formula of four preferred forms of thehydromonobenzoporphyrin derivatives of the green porphyrins illustratedin formulae 3 and 4 of FIG. 18.

FIGS. 21A-B illustrate the formulae for specific examples ofpyrrole-based macrocycle derivatives and xanthene derivatives which arepreferred for inclusion in microbubbles to enhance rupture of themicrobubbles upon activation.

FIGS. 22A-I schematically summarize the synthesis of an oligonucleotideconjugate of a texaphyrin metal complex.

FIGS. 23A-H illustrate the covalent coupling of texaphyrin metalcomplexes with amine, thiol, or hydroxy linked oligonucleotides.

FIGS. 24A-F illustrate the synthesis of diformyl monoic acid andoligonucleotide conjugate.

FIGS. 25A-J illustrate the synthesis of a texaphyrin based lightactivated drug.

FIG. 26 illustrates the formula for tin ethyl etiopurpurin (SnEt₂).

DETAILED DESCRIPTION

The present invention relates to a method and catheter for delivering alight activated drug to a tissue site and delivering ultrasound energyto the light activated drug within the tissue site. Since many lightactivated drugs are also activated by ultrasound energy, the delivery ofultrasound energy to the light activated drug activates the lightactivated drug within the tissue site. Similar to activation of a lightactivated drug by light, activation by ultrasound causes death oftissues within the tissue site. The tissue death is believed to resultfrom the release of a singlet oxygen. Suitable tissue sites include, butare not limited to, atheroma, cancerous tumors, thrombi and potentialrestenosis sites. A potential restenosis site is a tissue site whererestenosis is likely to occur such as the portion of vessels previouslytreated by balloon angioplasty. In contrast to light, ultrasound energycan be transmitted through opaque tissues. As a result, the ultrasoundenergy can be used to treat tissues which are deeper within a tissuesite than could be treated via light activation.

One explanation for the activation of light activated drugs via theapplication of ultrasound is a result of cavitation. Cavitation is knownto occur when ultrasonic energy above a certain threshold is applied toa liquid. The mechanism of generation of cavitation is described inApfel, Robert E., “Sonic Effervescence: Tutorial on Acoustic Cavitation”Journal of Acoustic Society of America 101 (3): 1227-1237 (March 1997)and Atchley A., Crum L., “Ultrasound—Its Chemical, Physical andBiological Effects: Acoustic Cavitation and Bubble Dynamics,” pp. 1-64,1988 VCH Publishers, New York (1998).

Cavitation results when gas dissolved in a solution forms bubbles undercertain types of acoustic vibration. Cavitation can also occur whensmall bubbles already present in the solution oscillate or repeatedlyenlarge and contract to become bubbles. When the size of thesecavitation bubbles reaches a size that cannot be maintained, theysuddenly collapse and release various types of energy. The various typesof energy include, but are not limited to, mechanical energy, visiblelight, ultraviolet light and other types of electromagnetic radiation.Heat, plasma, magnetic fields, shock waves, free radicals, heat andother forms of energy are also thought to be generated locally. Thelight activated drug is believed to be activated by at least one of thevarious forms of energy generated at the time of cavitation collapse.

The delivery of light activated drug to the tissue site can be throughtraditional systemic administration of a media including the lightactivated drug or can be performed through localized delivery of themedia. Localized delivery can be achieved through injection into thetissue site or through other traditional localized delivery techniques.A preferred delivery technique is using a catheter which includes amedia delivery lumen coupled with a media delivery port. The cathetercan be positioned such that the media delivery port is within the tissuesite or is adjacent to the tissue site via traditionalover-the-guidewire techniques. The media can then be locally deliveredto the tissue site through the media delivery port.

The localized delivery of the light activated drug to the tissue sightserves to localize the light activated drug within the tissue site andcan reduce the amount of light activated drug which concentrates intissues outside the tissue site. Further, localized delivery of thelight activated drug can serve to increase the concentration of thelight activated drug within the tissue site above levels which would beachieved through systemic delivery of the light activated drug.Alternatively, the same concentration of light activated drug within thetissue site as would occur through systemic administration can beachieved by introducing smaller amounts of light activated drug into apatient's body.

Localized delivery of the light activated drug also permits treatment oftissue sites which do not have selective uptake of the light activateddrug. As discussed above, many light activated drugs, such as thetexaphyrins, are taken up by most tissues within the body and laterlocalize within lipid rich tissues. As a result, a non-lipid rich tissuesite can be treated by delivering the ultrasound energy to the tissuesite before the light activated drug has an opportunity to localize inlipid rich tissues.

Localized delivery is also advantageous when the tissue site is lipidrich such as in an atheroma or a tumor. The localized delivery of thelight activated drug combined with the inherent affinity of the lightactivated drug for tissue site can result in a high degree oflocalization of the light activated drug within lipid rich tissue sites.

To increase localization of the light activated drug within the tissuesite, the light activated drug can be coupled with a sight directingmolecule to form a light activated drug conjugate. The site directingmolecule is chosen so the light activated drug conjugate specificallybinds with the tissue site when the light activated drug conjugate iscontacted with the tissue site under physiological conditions oftemperature and pH. The specific binding may result from specificelectrostatic, hydrophobic, entropic, or other interactions betweencertain residues on the conjugate and specific residues on the tissuesite.

In one preferred embodiment, the light activated drug includes anoligonucleotide acting as a site specific molecule coupled with atexaphyrin. The oligonucleotide can have an affinity for a targeted siteon a DNA strand. For instance, the oligonucleotide can be designed tohave complementary Watson-Crick base pairing with the targeted DNA site.Activation of the light activated drug after the conjugate has bound thetargeted DNA site can cause cleavage of the DNA strand at the targetedDNA site. As a result, the activated conjugate can be used for cleavageof targeted DNA sites. The light activated conjugate can be targeted toa site on viral DNA where activation of the light activated conjugatecauses the virus to be killed. Similarly, the light activated conjugatecan be targeted to oncogenes. Other applications of targeted DNAcleavage include, but are not limited to, antisense applications,specific cleavage and subsequent recombination of DNA; destruction ofviral DNA; construction of probes for controlling gene expression at thecellular level and for diagnosis; and cleavage of DNA in footprintinganalyses, DNA sequencing, chromosome analysis, gene isolation,recombinant DNA manipulations, mapping of large genomes and chromosomes,in chemotherapy and in site directing mutagenesis.

In another preferred embodiment, the light activated drug includes ahormone. The hormone may be targeted to a particular biological receptorwhich is localized at the tissue site.

The light activated drug can be included within several media suitablefor delivery into the body. Many light activated drugs are known to havelow water solubilities of less than 100 mg/L. As a result, achieving thedesired concentration of light activated drug in an aqueous solutionmedia for systemic delivery can often be difficult. However, localizeddelivery of the light activated drug requires a lower concentration oflight activated drug within the media. As a result, when the lightactivated drug is delivered locally, the light activated drug can beincluded in an aqueous solution.

The media can also be an emulsion which includes a lipoid as ahydrophobic phase dispersed in a hydrophilic phase. These emulsionsprovide a media which is safe for delivery into the body with aneffective concentration of light activated drug.

The media can also include microbubbles comprised from a substrate whichforms a shell. Suitable substrates for the microbubble include, but arenot limited to, biocompatible polymers, albumins, lipids, sugars orother substances. The light activated drug can be enclosed within themicrobubble, coupled with the shell and/or distributed in the mediaoutside the microbubble. A preferred microbubble comprises a lipidsubstrate such as liposome. Systemic administration of liposomes withlight activated drug has been shown to result in an increasedaccumulation and more prolonged retention of light activated drugswithin cultured malignant cells and within tumors in vivo. Jori et al.,Br. J. Cancer, 48:307-309 (1983); Cozzani et al., In Porphyrins in TumorPhototherapy, 173-183, Plenum Press (Andreoni et al. eds. 1984). As aresult, inclusion of the light activated drug within a liposome combinedwith the localized delivery of the light activated drug can serve toenhance the localization of the light activated drug within the tissuesite.

Including a light activated drug with the microbubbles has numerousadvantages over microbubbles without light activated drug. Afteradministration of microbubbles to a patient, the microbubbles often mustbe ruptured to achieve their therapeutic effects. One technique forrupturing microbubbles has been to expose the microbubbles to ultrasoundenergy. However, ultrasound energy of undesirably high intensity isfrequently required to break the microbubbles. Further, the ultrasoundenergy frequently must be matched to the resonant frequency of themicrobubbles. As a result, rupturing the microbubbles with ultrasoundcan present numerous challenges.

Activating a light activated drug within the microbubble and/or in thesubstrate of the microbubble can cause the microbubble to rupture.Activation of the light activated drug is believed to cause adisturbance which disrupts the shell of the microbubble enough to causethe microbubble to rupture. This disruption occurs when the lightactivated drug is coupled with the shell of the microbubble or isentirely within the microbubble. This disruption is also believed tooccur when light activated drug located the media outside themicrobubbles is activated in proximity of the microbubble. Accordingly,including a sufficient concentration light activated drug in the mediaoutside the microbubble and activating a portion of that light activateddrug can also cause rupture of the microbubbles. As a result,microbubbles can be ruptured by activating light activated drugs andwithout matching the ultrasound frequency to the resonant frequency ofthe microbubble. However, a more efficient rupturing of microbubbles canbe achieved by delivering a level of ultrasound energy which isappropriate to activate the light activated drug and which is matched tothe resonant frequency of the microbubble. Further, the cavitationthreshold can require an ultrasound intensity which is lower than theintensity required to rupture microbubbles without light activateddrugs. As a result, including light activated drug with microbubbles canreduce the intensity of ultrasound energy required to rupture themicrobubble.

The threshold value of cavitation is also reduced in the proximity ofmany light activated drugs. As a result, the light activated drugencourages cavitation in the proximity of the light activated drug.

The interior of the microbubbles may include a gas or may be devoid ofgas. When a gas is present, the gas can occupy any portion of themicrobubble's volume but preferably occupies 0.01-50% of the volume ofthe microbubble interior, more preferably 5-30% and most preferably10-20%. When the volume of gas is less than 0.01% of the volume,cavitation can be hindered and when the volume of gas is greater than50% the structural integrity of the microbubble shell can become tooweak for the microbubble to be transported to the tissue site. Suitablegasses for the interior of the microbubbles include, but are not limitedto, biocompatible gasses such as air, nitrogen, carbon dioxide, oxygen,argon, fluorine, xenon, neon, helium, or combinations thereof. Thepresence of tiny bubbles is known to reduce the cavitation threshold. Asa result, the presence of an appropriately sized gas bubble in themicrobubble can enhance cavitation in the proximity of the lightactivated drug.

The microbubbles are preferably 0.01-100 μm in diameter. This sizemicrobubble reduces excretion of the microbubble outside the body andalso reduces interference of the microbubble with the flow of fluidswithin the body of the patient. Further, the microbubbles preferablyhave a shell thickness of 0.001-50 μm, 0.01-5 μm and 0.1-0.5 μm. Thisthickness provides the shells with sufficient thickness that themicrobubble can withstand enough of the forces within the vasculature ofa patient to be transported through at least a portion of the patient'svasculature. Similarly, the thickness can permit the microbubbles to betransported through a lumen in an apparatus such as a catheter. However,this thickness is also sufficiently thin that alteration of theultrasound activated substance upon activation is sufficient to disruptthe shell of the microbubble and cause the microbubble rupture.

Activating the light activated drug to rupture microbubbles can causethe light activated drug to be released from the microbubble so thelight activated drug can penetrate the tissue near the site of rupture.Further exposure of the light activated drug to ultrasound can activatethe light activated drug within the tissue and cause death of the tissueas described above.

The microbubble can include a therapeutic in addition to the lightactivated drug. Activation of the light activated drug can serve torupture the microbubble and release the therapeutic from themicrobubble. As a result, the therapeutic is released in proximity to atissue site by rupturing the microbubble in proximity to the tissuesite. This is advantageous when the therapeutic can be detrimental whenadministered systemically. For instance, a therapeutic such as cisplatinis known to kill cancerous tissues but is also known to kill othertissues throughout the body. As a result, systemic administration ofcisplatin can be detrimental. However, microbubbles can serve to protecttissues from the therapeutic agent until the therapeutic agent isreleased from the carrier. For instance, when the therapeutic isenclosed within the interior of the microbubble, contact between thetherapeutic agent and tissues outside the carrier is reduced. As aresult, the carrier increases protection of tissues outside the carrierare protected from the therapeutic agent until the microbubble isruptured and the therapeutic released.

The therapeutics may be encapsulated in the microbubbles, included inthe shell of the microbubbles or in the media outside the microbubbles.Therapeutic, as used herein, means an agent having beneficial effect onthe patient.

Examples of therapeutics which can be included with the microbubblesinclude, but are not limited to, hormone products such as, vasopressinand oxytocin and their derivatives, glucagon and thyroid agents asiodine products and anti-thyroid agents; cardiovascular products aschelating agents and mercurial diuretics and cardiac glycosides;respiratory products as xanthine derivatives (theophylline &aminophylline); anti-infectives as aminoglycosides, antifungals(amphotericin), penicillin and cephalosporin antibiotics, antiviralagents as Zidovudine, Ribavirin, Amantadine, Vidarabine, and Acyclovir,anti-helmintics, antimalarials, and antituberculous drugs; biologicalsas immune serums, antitoxins and antivenins, rabies prophylaxisproducts, bacterial vaccine, viral vaccines, toxoids; antineoplasticsasnitrosureas, nitrogen mustards, antimetabolites (fluorouracil,hormones, asprogesings and estrogens and antiestrogens; antibiotics asDactinomycin; mitotic inhibitors as Etoposide and the Vinca alkaloids,Radiopharmaceuticals as radioactive iodine and phosphorus products; aswell as Interferon, hydroxyurea, procarbazine, Dacarbazine, Mitotane,Asparaginase and cyclosporins.

Other suitable therapeutics include, but are not limited to:thrombolytic agents such as urokinase; coagulants such as thrombin;antineoplastic agents, such as platinum compounds (e.g., spiroplatin,cisplatin, and carboplatin), methotrexate, adriamycin, taxol, mitomycin,ansamitocin, bleomycin, cytosine arabinoside, arabinosyl adsnine,mercaptopolylysine, vincristine, busulfan, chlorambucil, melphalan(e.g.,PAM, L-PAM or phenylalanine mustard), mercaptopurine, mitotane,procarbazine hydrochloride dactinomycin (actinomycin D),daunorubicinhydrochloride, doxorubicin hydrochloride, mitomycin,plicamycin (mithramycin), aminoglutethimide, estramustine phosphatesodium, flutamide, leuprolide acetate, megestrol acetate, tamoxifencitrate, testolactone, trilostane, amsacrine (m-AMSA), asparaginase(L-asparaginase) Erwinaasparaginase, etoposide (VP-16), interferon alpha-2a, interferon alpha-2b, teniposide (VM-26), vinblastine sulfate (VLB),vincristine sulfate, bleomycin, bleomycin sulfate, methotrexate,adriamycin, and arabinosyl; blood products such as parenteral iron,hemin; biological response modifiers such as muramyldipeptide,muramyltripeptide, microbial cell wall components, lymphokines(e.g.,bacterial endotoxin such as lipopolysaccharide, macrophageactivationfactor), sub-units of bacteria (such as Mycobacteria,Corynebacteria), the synthetic dipeptideN-acetyl-muramyl-L-alanyl-D-isoglutamine; anti-fungalagents such asketoconazole, nystatin, griseofulvin, flucytosine (5-fc), miconazole,amphotericin B, ricin, and beta -lactam antibiotics (e.g.,sulfazecin);hormones such as growth hormone, melanocyte stimulating hormone,estradiol, beclomethasone dipropionate, betamethasone,betamethasoneacetate and betamethasone sodium phosphate,vetamethasonedisodiumphosphate, vetamethasone sodium phosphate,cortisone acetate, dexamethasone, dexamethasone acetate, dexamethasonesodium phosphate, flunsolide, hydrocortisone, hydrocortisone acetate,hydrocortisonecypionate, hydrocortisone sodium phosphate, hydrocortisonesodium succinate, methylprednisolone, methylprednisolone acetate,methylprednisolonesodium succinate, paramethasone acetate, prednisolone,prednisoloneacetate, prednisolone sodium phosphate, prednisolonerebutate, prednisone, triamcinolone, triamcinolone acetonide,triamcinolone diacetate, triamcinolone hexacetonide and fludrocortisoneacetate; vitamins such ascyanocobalamin neinoic acid, retinoids andderivatives such as retinolpalmitate, and alpha -tocopherol; peptides,such as manganese super oxidedimutase; enzymes such as alkalinephosphatase; anti-allergic agents such as amelexanox; anti-coagulationagents such as phenprocoumon and heparin; circulatory drugs such aspropranolol; metabolic potentiators such asglutathione; antitubercularssuch as para-aminosalicylic acid, isoniazid, capreomycin sulfatecycloserine, ethambutol hydrochloride ethionamide, pyrazinamide,rifampin, and streptomycin sulfate; antivirals such as acyclovir,amantadine azidothymidine (AZT or Zidovudine), Ribavirin andvidarabinemonohydrate (adenine arabinoside, ara-A); antianginals such asdiltiazem,nifedipine, verapamil, erythrityl tetranitrate, isosorbidedinitrate,nitroglycerin (glyceryl trinitrate) and pentaerythritoltetranitrate;anticoagulants such as phenprocoumon, heparin; antibiotics such asdapsone, chloramphenicol neomycin, cefaclor, cefadroxil, cephalexin,cephradine erythromycin, clindamycin, lincomycin, amoxicillin,ampicillin, bacampicillin, carbenicillin, dicloxacillin, cyclacillin,picloxacillin, hetacillin, methicillin, nafcillin, oxacillin, penicillinG, penicillin V, ticarcillin rifampin and tetracycline;antiinflammatories such as difunisal, ibuprofen, indomethacin,meclofenamate, mefenamic acid, naproxen, oxyphenbutazone,phenylbutazone, piroxicam, sulindac, tolmetin, aspirin and salicylates;antiprotozoans such as chloroquine, hydroxychloroquine, metronidazole,quinine and meglumine antimonate; antirheumatics such as penicillamine;narcotics such as paregoric; opiates such as codeine, heroin, methadone,morphine and opium; cardiac glycosides such as deslanoside, digitoxin,digoxin, digitalin and digitalis; neuromuscular blockers such asatracurium besylate, gallamine triethiodide, hexafluorenium bromide,metocurine iodide, pancuronium bromide, succinylcholine chloride(suxamethonium chloride), tubocurarine chloride and vecuronium bromide;sedatives (hypnotics) such as amobarbital, amobarbital sodium,aprobarbital, butabarbital sodium, chloral hydrate, ethchlorvynol,ethinamate, flurazepam hydrochloride, glutethimide, methotrimeprazinehydrochloride, methyprylon, midazolam hydrochloride, paraldehyde,pentobarbital, pentobarbital sodium, phenobarbital sodium, secobarbitalsodium, talbutal, temazepam and triazolam; local anesthetics such asbupivacaine hydrochloride, chloroprocaine hydrochloride,etidocainehydrochloride, lidocaine hydrochloride, mepivacainehydrochloride, procainehydrochloride and tetracaine hydrochloride;general anesthetics such asdroperidol, etomidate, fentanyl citrate withdroperidol, ketaminehydrochloride, methohexital sodium and thiopentalsodium; and radioactive particles or ions such as strontium, iodiderhenium and yttrium.

In certain preferred embodiments, the therapeutic is a monoclonalantibody, such as a monoclonal antibody capable of binding to melanomaantigen.

Other preferred therapeutics include genetic material such as nucleicacids, RNA, and DNA, of either natural or synthetic origin, includingrecombinant RNA and DNA and antisense RNA and DNA. Types of geneticmaterial that may be used include, for example, genes carried onexpression vectors such as plasmids, phagemids, cosmids, yeastartificial chromosomes (YACs), and defective or “helper” viruses,antigene nucleic acids, both single and double stranded RNA and DNA andanalogs thereof, such asphosphorothioate and phosphorodithioateoligodeoxynucleotides. Additionally, the genetic material may becombined, for example, with proteins or other polymers.

Examples of genetic therapeutics that may be included in themicrobubbles include DNA encoding at least a portion of an HLAgene, DNAencoding at least a portion of dystrophin, DNA encoding at least aportion of CFTR, DNA encoding at least a portion of IL-2, DNA encodingat least a portion of TNF, an antisense oligonucleotide capable ofbinding the DNA encoding at least a portion of Ras.

DNA encoding certain proteins may be used in the treatment of manydifferent types of diseases. For example, adenosine deaminase may beprovided to treat ADA deficiency; tumor necrosis factor and/orinterleukin-2 may be provided to treat advanced cancers; HDL receptormay be provided to treat liver disease; thymidine kinase may be providedto treat ovarian cancer, brain tumors, or HIV infection; HLA-B7 may beprovided to treat malignant melanoma; interleukin-2 may be provided totreat neuroblastoma, malignant melanoma, or kidney cancer; interleukin-4may be provided to treat cancer; HIV env may be provided to treat HIVinfection; antisense ras/p53 may be provided to treat lung cancer; andFactor VIII may be provided to treat Hemophilia B. See, for example,Science 258, 744-746.

If desired, more than one therapeutic may be included in the media Forexample, a single microbubble may contain more than one therapeutic ormicrobubbles containing different therapeutics may be co-administered.By way of example, a monoclonal antibody capable of binding to melanomaantigen and an oligonucleotide encoding at least a portion of IL-2 maybe administered in a single microbubble. The phrase “at least a portionof,” as used herein, means that the entire gene need not be representedby the oligonucleotide, so long as the portion of the gene representedprovides an effective block to gene expression. Further, microbubblesincluding a therapeutic can be administered before, after, during orintermittently with the administration of microbubbles without atherapeutic. For instance, microbubbles without a therapeutic andmicrobubbles including a coagulant such as thrombin can be administeredto a patient having liver cancer. Activating the light activated drugincluded with the microbubbles serves to rupture the microbubbles andrelease the light activated drug and thrombin from the microbubbles.Further activation of the light activated drug can cause tissue deathand the thrombin can cause coagulation in and around the damagedtissues.

Prodrugs may be included in the microbubbles, and are included withinthe ambit of the term therapeutic, as used herein. Prodrugs are wellknown in the art and include inactive drug precursors which, whenexposed to high temperature, metabolizing enzymes, cavitation and/orpressure, in the presence of oxygen or otherwise, or when released fromthe microbubbles, will form active drugs. Such prodrugs can be activatedvia the application of ultrasound to the prodrug-containing microbubbleswith the resultant cavitation, heating, pressure, and/or release fromthe microbubbles. Suitable prodrugs will be apparent to those skilled inthe art, and are described, for example, in Sinkula et al., J. Pharm.Sci. 1975 64, 181-210, the disclosure of which is hereby incorporatedherein by reference in its entirety. Prodrugs, for example, may compriseinactive forms of the active drugs wherein a chemical group is presenton the prodrug which renders it inactive and/or confers solubility orsome other property to the drug. In this form, the prodrugs aregenerally inactive, but once the chemical group has been cleaved fromthe prodrug, by heat, cavitation, pressure, and/or by enzymes in thesurrounding environment or otherwise, the active drug is generated. Suchprodrugs are well described in the art and comprise a wide variety ofdrugs bound to chemical groups through bonds such as esters to short,medium or long chain aliphatic carbonates, hemiesters of organicphosphate, pyrophosphate, sulfate, amides, amino acids, azo bonds,carbamate, phosphamide, glucosiduronate, N-acetylglucosamine andbeta-glucoside. Examples of drugs with the parent molecule and thereversible modification or linkage are as follows: convallatoxin withketals, hydantoin with alkyl esters, chlorphenesin with glycine oralanins esters, acetaminophen with caffeine complex, acetylsalicylicacid with THAM salt, acetylsalicylic acid with acetamidophenyl ester,naloxone with sulfateester, 15-methylprostaglandin F sub 2 with methylester, procaine with polyethylene glycol, erythromycin with alkylesters, clindamycin with alkylesters or phosphate esters, tetracyclinewith betains salts, 7-acylaminocephalosporins with ring-substitutedacyloxybenzyl esters, nandrolone with phenylproprionate decanoateesters, estradiol with enolether acetal, methylprednisolone with acetateesters, testosterone with n-acetylglucosaminide glucosiduronate(trimethylsilyl) ether, cortisol or prednisolone or dexamethasone with21-phosphate esters. Prodrugs may also be designed as reversible drugderivatives and utilized as modifiers to enhance drug transport tosite-specific tissues. Examples of parent molecules with reversiblemodifications or linkages to influence transport to a site specifictissue and for enhanced therapeutic effect include isocyanate withhaloalkyl nitrosurea, testosterone with propionateester, methotrexate(3-5′-dichloromethotrexate) with dialkyl esters, cytosine arabinosidewith 5′-acylate, nitrogen mustard (2,2′-dichloro-N-methyldiethylamine),nitrogen mustard with aminomethyltetracycline, nitrogen mustard withcholesterol or estradiol ordehydroepiandrosterone esters and nitrogenmustard with azobenzene. As one skilled in the art would recognize, aparticular chemical group to modify a given drug may be selected toinfluence the partitioning of the drug into either the shell or theinterior of the microbubbles. The bond selected to link the chemicalgroup to the drug may be selected to have the desired rate ofmetabolism, e.g., hydrolysis in the case of ester bonds in the presenceof serum esterases after release from the microbubbles. Additionally,the particular chemical group may be selected to influence thebiodistribution of the drug employed in the microbubbles, e.g.,N,N-bis(2-chloroethyl)-phosphorodiamidicacid with cyclic phosphoramidefor ovarian adenocarcinoma. Additionally, the prodrugs employed withinthe microbubbles may be designed to contain reversible derivatives whichare utilized as modifiers of duration of activity to provide, prolong ordepot action effects. For example, nicotinic acid may be modified withdextran and carboxymethlydextran esters, streptomycin with alginic acidsalt, dihydrostreptomycin with pamoate salt, cytarabine (ara-C) with5′-adamantoats ester, ara-adenosine (ara-A) with 5-palmirate and5′-benzoate esters, amphotericin B with methyl esters, testosterone with17-beta -alkyl esters, estradiol with formate ester, prostaglandin with2-(4imidazolyl) ethylamine salt, dopamine with amino acid amides,chloramphenicol with mono- and bis(trimethylsilyl) ethers, andcycloguanil with pamoate salt. In this form, a depot or reservoir oflong-acting drug may be released in vivo from the prodrug bearingmicrobubbles. In addition, compounds which are generally thermallylabile may be utilized to create toxic free radical compounds. Compoundswith azolinkages, peroxides and disulfide linkages which decompose withhigh temperature are preferred. With this form of prodrug, azo, peroxideor disulfide bond containing compounds are activated by cavitationand/or increased heating caused by the interaction of ultra with themicrobubbles to create cascades of free radicals from these prodrugsentrapped therein. A wide variety of drugs or chemicals may constitutethese prodrugs, such as azo compounds, the general structure of suchcompounds being R—N═N—R, wherein R is a hydrocarbon chain, where thedouble bond between the two nitrogen atoms may react to create freeradical products in vivo. Exemplary drugs or compounds which may be usedto create free radical products include azo containing compounds such asazobenzene,2,2′-azobisisobutyronitrile, azodicarbonamide, azolitmin,azomycin, azosemide, azosulfamide, azoxybenzene, aztreonam, sudan III,sulfachrysoidine, sulfamidochrysoidine and sulfasalazine, compoundscontaining disulfide bonds such as sulbentine, thiamine disulfide,thiolutin, thiram, compounds containing peroxides such as hydrogenperoxide and benzoylperoxide, 2,2′-azobisisobutyronitrile,2,2′-azobis(2-amidopropane) dihydrochloride, and2,2′-azobis(2,4dimethylvaleronitrile). A microbubble having oxygen gason its interior should create extensive free radicals with cavitation.Also, metal ions from the transition series, especially manganese, ironand copper can increase the rate of formation of reactive oxygenintermediates from oxygen. By including metal ions within themicrobubbles, the formation of free radicals in vivo can be increased.These metal ions may be incorporated into the microbubbles as freesalts,as complexes, e.g., with EDTA, DTPA, DOTA or desferrioxamine, orasoxides of the metal ions. Additionally, derivatized complexes of themetal ions may be bound to lipid head groups, or lipophilic complexes ofthe ions may be incorporated into a lipid bilayer, for example. Whenexposed to thermal stimulation, e.g., cavitation, these metal ions thenwill increase the rate of formation of reactive oxygen intermediates.Further, radiosensitizers such as metronidazole and misonidazole may beincorporated into the gas-filled liposomes to create free radicals onthermal stimulation. By way of an example of the use of prodrugs, anacylated chemical group may be bound to a drug via an ester linkagewhich would readily cleave in vivo by enzymatic action in serum. Theacylated prodrug can be included in the microbubble. When themicrobubble is ruptured, the prodrug will then be exposed to the serum.The ester linkage is then cleaved by esterases in the serum, therebygenerating the drug. Similarly, ultrasound may be utilized not only toactivate the light activated drug so as to burst the gas-filledliposome, but also to cause thermal effects which may increase the rateof the chemical cleavage and the release of the active drug from theprodrug. The microbubbles may also be designed so that there is asymmetric or an asymmetric distribution of the therapeutic both insideand outside of the microbubble. The particular chemical structure of thetherapeutics may be selected or modified to achieve desired solubilitysuch that the therapeutic may either be encapsulated within the interiorof the microbubble or couple with the shell of the microbubble. Theshell-bound therapeutic may bear one or more acyl chains such that, whenthe microbubble is popped or heated or ruptured via cavitation, theacylated therapeutic may then leave the surface and/or the therapeuticmay be cleaved from the acyl chains chemical group. Similarly, othertherapeutics may be formulated with a hydrophobic group which isaromatic or sterol in structure to incorporate into the surface of themicrobubble.

When the microbubble is a liposome, the liposomes can be “fastbreaking”. In fast breaking liposomes, the light activated drug-liposomecombination is stable in vitro but, when administered in vivo, the lightactivated drug is rapidly released into the bloodstream where it canassociate with serum lipoproteins. As a result, the localized deliveryof liposomes combined with the fast breaking nature of the liposomes canresult in localization of the light activated drug and/or thetherapeutic in the tissues near the catheter. Further, the fast breakingliposomes can prevent the liposomes from leaving the vicinity of thecatheter intact and then concentrating in non-targeted tissues such asthe liver. Delivery of ultrasound energy from the catheter can alsoserve to break apart the liposomes after they have been delivered fromthe catheter.

A catheter for locally delivering a media including a light activateddrug includes an elongated body with at least one utility lumenextending through the elongated body. The utility lumens can be used todeliver the media including the light activated drug locally to a tissuesite and/or to receive a guidewire so the catheter can be guided to thetissue site. The ultrasound assembly can include an ultrasoundtransducer designed to transmit ultrasound energy which activates thelight activated drug.

A support member can support the ultrasound transducer adjacent to anouter surface of the elongated body so as to define a chamber betweenthe ultrasound transducer and the elongated body. The chamber can befilled with a material which creates a low acoustic impedance to reducethe exposure of at least one utility lumen within the elongated body toultrasound energy delivered from the ultrasound transducer. Forinstance, the chamber can be filled with a material which absorbs,reflects or prevents transmission of ultrasound energy through thechamber. Alternatively, the chamber can be evacuated to reducetransmission of ultrasound energy through the chamber. Reducing theexposure of at least one lumen to the ultrasound energy reduces exposureof media delivered through the at least one lumen to the ultrasoundenergy. As a result, the effect of the ultrasound energy on the lightactivated drug is reduced until the light activated drug has beendelivered out of the catheter. Further, ultrasound energy is known torupture microbubbles. As a result, when the media includes microbubbles,the chamber reduces the opportunity for the ultrasound energy to rupturethe microbubbles within the catheter.

The support member can have ends which extend beyond the ultrasoundmember. As a result, the chamber can be positioned adjacent to theentire longitudinal length of the ultrasound transducer and can extendbeyond the ends of the ultrasound transducer. This configurationmaximizes the portion of the ultrasound transducer which is adjacent tothe chamber. Increasing the portion of ultrasound transducer adjacent tothe chamber can reduce the amount of ultrasound energy transmitted tothe utility lumens. The ultrasound assembly can include an outer coatingover the ultrasound transducer. Temperature sensors can be positioned inthe outer coating adjacent to ultrasound transducer. The temperaturesensors feedback information regarding the temperature adjacent to theultrasound transducers where the thermal energy has a reducedopportunity to dissipate. As a result, the temperature sensors provide ameasure of the temperature on the exterior surface of the transducer.

FIGS. 1A-1B illustrates a catheter 10 for delivering a media including alight activated drug to a tissue site. The catheter 10 includes anultrasound assembly 12 for delivering ultrasound energy to lightactivated drug within the tissue site. The catheter 10 includes anelongated body 14 with a utility lumen 16 extending through theelongated body 14. The utility lumen 16 can receive a guidewire (notshown) so the catheter 10 can be threaded along the guidewire. Theutility lumen 16 can also be used for the delivering media which includea light activated drug. A fiber optic can also be positioned in theutility lumen 16 to provide a view of the tissue site or to providelight to the tissue site. As a result, the catheter can also be used asan endoscope.

The ultrasound assembly 12 can also include an outer coating 18.Suitable outer coatings 18 include, but are not limited to, polyimide,parylene and polyester. An ultrasound transducer 20 is positioned withinthe outer coating 18. Suitable ultrasound transducers 20 include, butare not limited to, PZT-4D, PZT-4, PZT-8 and cylindrically shapedpiezoceramics. When the ultrasound transducer 20 has a cylindricalshape, the ultrasound transducer 20 can encircle the elongated body 14as illustrated in FIG. 1C. One or more temperature sensors 22 can bepositioned in the outer coating 18. The temperature sensors 22 can bepositioned adjacent to the ultrasound transducer 20 to provide feedbackregarding the temperature adjacent to the ultrasound transducer 20. Thetemperature sensors can be in electrical communication with anelectrical coupling 24. The electrical coupling 24 can be coupled with afeedback control system (not shown) which adjusts the level of theultrasound energy delivered from the ultrasound transducer 20 inresponse to the temperature at the temperature sensors 22.

The catheter 10 can include a perfusion lumen 25. The perfusion lumen 25allows fluid to flow from outside the catheter into the utility lumen16. Once a guidewire has been removed from the utility lumen 16, fluidflow which is obstructed by the ultrasound assembly can continue throughthe perfusion lumen 25 and the utility lumen.

As illustrated in FIGS. 2A-2B, the ultrasound assembly 12 can be flushwith the elongated body 14. Further, the ultrasound transducer 20 andthe temperature sensors 22 can be positioned within the elongated body14. This configuration of elongated body 14 and ultrasound transducer 20can eliminate the need for the outer coating 18 illustrated in FIGS.1A-1C.

As illustrated in FIG. 3A, the catheter 10 can also include a mediadelivery port 26, a media inlet port 28 and a second utility lumen 16A.The media inlet port 28 is designed to be coupled with a media source(not shown). Media can be transported from the media source and throughthe media delivery port 26 via the second utility lumen 16A. As aresult, a guidewire can be left within the utility lumen 16 while mediais delivered via the second utility lumen 16A.

FIG. 4A illustrates a catheter 10 including a plurality of ultrasoundassemblies 12. FIGS. 4B-4C are cross sections of a catheter 10 with asecond utility lumen 16A coupled with the media delivery ports 26. Thesecond utility lumen 16A can also be coupled with the media inlet port28 illustrated in FIG. 4A. The media inlet port 28 is designed to becoupled with a media source (not shown). Media can be transported fromthe media source and through the media delivery ports 26 via the secondutility lumen 16A.

The catheter 10 can include a balloon 30 as illustrated in FIG. 5A. Theballoon 30 can be constructed from an impermeable material or apermeable membrane or a selectively permeable membrane which allowscertain media to flow through the membrane while preventing other mediafrom flowing through the membrane. Suitable membranous materials for theballoon 30 include, but are not limited to cellulose, cellulose acetate,polyvinylchloride, polyolefin, polyurethane and polysulfone. When theballoon 30 is constructed from a permeable membrane or a selectivelypermeable membrane, the membrane pore sizes are preferably 5 A-2 μm,more preferably 50 A-900 A and most preferably 100 A-300 A in diameter.

As illustrated in FIG. 5B, an ultrasound assembly 12, a first mediadelivery port 26A and a second media delivery port 26B can be positionedwithin the balloon 30. The first and second media delivery ports 26A,26B are coupled with a second utility lumen 16A and third utility lumen16B. The second and third utility lumens 16A , 16B can be coupled withthe same media inlet port 28 or with independent media inlet ports 28.When the first and second media delivery ports 26A, 26B are coupled withdifferent media inlet ports 28, different media can be delivered via thesecond and third media delivery ports 26A, 26B. For instance, amedication media can be delivered via the third utility lumen 16B and anexpansion media can be delivered via the second utility lumen 16A. Themedication media can include drugs or other medicaments which canprovide a therapeutic effect The expansion media can serve to expand theballoon 30 or wet the membrane comprising the balloon 30. Wetting themembrane comprising the balloon 30 can cause a minimally permeablemembrane to become permeable.

The ultrasound assembly 12 can be positioned outside the balloon 30 asillustrated in FIGS. 6A-6C. In FIG. 6A the balloon 30 is positioneddistally of the ultrasound assembly 12 and in FIG. 6B the ultrasoundassembly 12 is positioned distally of the balloon 30. FIG. 6C is a crosssection a catheter 10 with an ultrasound assembly 12 positioned outsidethe balloon 30. The catheter includes a second utility lumen 16A coupledwith a first media delivery port 26A. The second utility lumen 16A canbe used to deliver an expansion media and/or a medication media to theballoon 30. When the balloon 30 is constructed from a permeablemembrane, the medication media and/or the expansion media can passthrough the balloon 30. Similarly, when the balloon 30 is constructedfrom a selectively permeable membrane, particular components of themedication media and/or the expansion media can pass through the balloon30. Pressure can be used to drive the media or components of the mediaacross the balloon 30. Other means such as phoresis can also be used todrive the media or components of the media across the balloon 30.

As illustrated in FIG. 6C, the ultrasound assembly 12 may be positionedat the distal end of the catheter 10. The second utility lumen 16A canbe used to deliver an expansion media and/or a medication media to theballoon 30. The utility lumen 16 can be used to deliver a medicationmedia as well as to guide the catheter 10 along a guidewire.

As illustrated in FIGS. 7A-7C, the catheter 10 can include a secondmedia assembly 12 and the second media delivery port 26B are positioneddistally relative to a balloon 30, however, the balloon 30 can bepositioned distally relative to the ultrasound assembly 12 and thesecond media delivery port 26B. In FIG. 7A the ultrasound assembly 12 ispositioned distally of the second media delivery port 26B and in FIG. 7Bthe second media delivery port 26B is positioned distally of theultrasound assembly 12.

FIG. 7C is a cross section of the catheter 10 illustrated in FIG. 7A.The catheter 10 includes first and second media delivery ports 26A, 26Bcoupled with a second utility lumen 16A and third utility lumen 16B. Thesecond and third utility lumens 16A, 16B can be coupled with independentmedia inlet ports 28 (not shown). The second utility lumen 16A can beused to deliver an expansion media and/or a medication media to theballoon 30 while the third utility lumen 16B can be used to deliver amedication media through the second media delivery port 26B.

As illustrated in FIGS. 8A-8B, the catheter 10 can include a firstballoon 30A and a second balloon 30B. The ultrasound assembly 12 can bepositioned between the first and second balloons 30A, 30B. A secondmedia delivery port 26B can optionally be positioned between the firstand second balloons 30A, 30B. In FIG. 8A the second media delivery port26B is positioned distally relative to the ultrasound assembly and inFIG. 8B the ultrasound assembly is positioned distally relative to thesecond media delivery port 26B.

FIG. 8C is a cross section of the first balloon 30A illustrated in FIG.8B. The catheter includes a second, third and fourth utility lumens 16A,16B, 16C. The second utility lumen 16A is coupled with a first mediadelivery port 26A within the first balloon. The third utility lumen 16Bis coupled with the second media delivery port 26B and the fourthutility lumen 16C is coupled with a third media delivery port 26C in thesecond balloon 30B (not shown). The second and fourth utility lumens16A, 16C can be used to deliver expansion media and/or medication mediato the first and second balloon 30A, 30B. The second and fourth utilitylumens 16A, 16C can be coupled with the same media inlet port or withindependent media inlet ports (not shown). When the second and fourthutility lumens are coupled with the same media inlet port, the pressurewithin the first and second balloons 30A, 30B will be similar. When thesecond and fourth utility lumens are coupled with independent mediainlet ports, different pressures can be created within the first andsecond balloons 30A, 30B. The third utility lumen 16B can be coupledwith an independent media inlet port and can be used to deliver amedication media via the second media delivery port 26B.

FIGS. 9A-91I illustrate operation of various embodiments of catheters 10for delivering ultrasound energy to a light activated drug within atissue site. FIGS. 9A-9I illustrate the tissue site 32 as an atheroma ina vessel 34, however, it is contemplated that the catheter 10 can beused with other tissue sites 32 such as a tumor and that the catheter 10can be positioned within the vasculature of the tumor. In each of FIGS.9A-9I, the catheter 10 is illustrated as being within a vessel 34. Thecatheter 10 can be positioned within the vessel 34 by applyingconventional over-the-guidewire techniques and can be verified byincluding radiopaque markers upon the catheter 10.

In FIG. 9A, the catheter 10 is positioned so the ultrasound assembly 12is adjacent to a tissue site 32 within a vessel 34. When the catheter 10is in position, the guidewire is removed from the utility lumen 16 andmedia can be delivered via the utility lumen 16 as illustrated by thearrows 36. In FIG. 9A, the media includes microbubbles 38 but canalternatively be an emulsion. The media is delivered to the tissue site32 via the utility lumen 16 and ultrasound energy 40 is delivered fromthe ultrasound assembly 12. Suitable periods for delivering theultrasound energy include., but are not limited to, 1 minute to threehours, 2 minutes to one hour and 10-30 minutes.

Suitable intensities for the ultrasound energy include, but are notlimited to, 0.1-1000 W/cm², 1-100 W/cm² and 10-50 W/cm². Suitablefrequencies for the ultrasound energy include, but are not lmited to, 10kHz-100 MHz and 10 kHz-50 MHz but is preferably 20 kHz-10 MHz. Suitableultrasound energies also include, but are not limited to 0.02 to 10w/cm² at a frequency of about 20 KHz to about 10 MHz and more preferablyabout 0.3 W/cm² at a frequency of about 1.3 MHz. The ultrasound energycan be intermittently switched between a first and second frequency toincrease the efficiency of microbubble rupture and to increaseactivation of the light activated drug. For instance, the ultrasoundenergy can be switched between about 100 kHz and about 270 kHz in shortpulses of approximately 0.001-10 seconds duration. Similarly, theultrasound energy can be switched between first and second intensities.When the catheter includes a plurality of ultrasound transducers as willbe discussed below, the first and second frequencies can be provided bydifferent ultrasound transducers. Similarly, the first and secondintensities can be provided by different ultrasound transducers.Further, when the catheter includes a plurality of ultrasoundtransducers each transducer can simultaneously transmit ultrasoundenergy with different intensity and/or frequency.

The delivery of ultrasound energy 40 can be before, after, during orintermittently with the delivery of the microbubbles 38. As discussedabove, the microbubbles 38 can be “fast breaking” so they rupture uponexiting the utility lumen and being exposed to the vessel 34. Asdescribed above, the ultrasound energy from the ultrasound assembly 12can cause the microbubbles 38 within the delivered media to rupture. Aswill be described in more detail below, the ultrasound assembly can bedesigned to reduce the exposure of media within the catheter 10 to theultrasound energy from the ultrasound assembly 12. When the catheter 10is so designed, the number of microbubbles 38 which rupture within thecatheter is reduced and the number of microbubbles 38 which ruptureoutside the catheter is increased.

Delivery of the ultrasound energy before delivery of the light activateddrug can enhance absorption of the light activated drug into the tissuesite. Delivery of the ultrasound energy a pre-determined time afterdelivery of the light activated drug can provide the light activateddrug time to penetrate the tissue site. The predetermined time can be ofsufficient duration that at least a portion of the light activated drugpenetrates into the tissue site. The predetermined time can also be ofsufficient duration that the light activated drug localizes within thelipid rich tissue of the atheroma. Sufficient time between delivery ofthe media and the ultrasound energy include but are not limited to, 1minute to 48 hours, 1 minute to 3 hours, 1 to 15 minutes and 1 to 2minutes. Once the light activated drug has penetrated the tissue site32, the ultrasound energy from the ultrasound assembly 12 can activatethe light activated dug within the tissue site 32 so as to cause tissuedeath within the tissue site 32.

In FIG. 9B, ultrasound energy 40 is delivered from the ultrasoundtransducer 20 and a media is delivered through the media delivery port26 as illustrated by the arrows 36. The delivery of ultrasound energy 40can be before, after, during or intermittently with the delivery of themedia via the media delivery port 26. As illustrated in FIG. 9C, theguidewire 104 can remain in the utility lumen 16 during the delivery ofthe media via the media delivery ports 26. As will be discussed infurther detail below, the ultrasound assembly can be designed to reducethe transmission of the ultrasound energy into the utility lumen.Because the transmission of ultrasound energy 40 into the utility lumen16 is reduced, the change in the frequency of the ultrasound transducer20 which is due to the presence of the guidewire in the utility lumen 16is also reduced.

In FIG. 9D, a catheter 10 including a balloon 30 is positioned with theballoon adjacent to the tissue site 32. In FIG. 9E, the balloon 30 isexpanded into contact with the tissue site 32. As discussed above, thecatheter 10 can include a perfusion lumen which permits a continuousflow of fluid from the vessel through the utility lumen during thepartial or full obstruction of the vessel by the balloon. When theballoon 30 is constructed from a membrane or a selectively permeablemembrane a media can be delivered to the tissue site 32 via the balloon30. The media can serve to wet the membrane or can include a drug orother medicament which provides a therapeutic effect. Ultrasound energy40 can be delivered from the ultrasound assembly 12 before, after,during or intermittently with the delivery of the media. The ultrasoundenergy 40 can serve to drive the media across the membrane viaphonophoresis or can enhance the therapeutic effect of the media

In FIG. 9F a catheter 10 with an ultrasound assembly 12 outside aballoon 30 is positioned at the tissue site 32 so the ultrasoundassembly 12 is adjacent to the tissue site 32. A fluid within the vesselflows past the balloon as indicated by the arrow 42. In FIG. 9G, theballoon 30 is expanded into contact with the vessel 34. The balloon 30can be constructed from an impermeable material so the vessel 34 isoccluded. As a result, the fluid flow through the vessel 34 is reducedor stopped. A medication media is delivered through the utility lumen 16and ultrasound energy 40 is delivered from the ultrasound assembly 12.In embodiments of the catheter 10 including a media delivery port 26outside of the balloon 30 (i.e. FIGS. 7A-7C), the medication media canbe delivered via the media delivery port 26. Further, a first medicationmedia can be delivered via the media delivery port 26 while a secondmedication media can be delivered via the utility lumen 16 or while aguidewire is positioned within the utility lumen 16. The ultrasoundenergy 40 can be delivered from the ultrasound assembly 12 before,after, during or intermittently with the delivery of the media. Theocclusion of the vessel 34 before the delivery of the media can serve toprevent the media from being swept from the tissue site 32 by the fluidflow. Although the balloon 30 illustrated in FIGS. 9F-9G is positionedproximally relative to the ultrasound assembly 12, the fluid flowthrough the vessel 34 can also be reduced by expanding a single balloon30 which is positioned distally relative to the ultrasound assembly 12.

In FIG. 9H a catheter 10 including a first balloon 30A and a secondballoon 30B is positioned at a tissue site 32 so the ultrasound assembly12 is positioned adjacent to the tissue site 32. A fluid within thevessel 34 flows past the balloon 30 as indicated by the arrow 42. InFIG. 91, the first and second balloons 30A, 30B are expanded intocontact with the vessel 34. The first and second balloons 30A, 30B canbe constructed from an impermeable material so the vessel 34 is occludedproximally and distally of the ultrasound assembly 12. As a result, thefluid flow adjacent to the tissue site 32 is reduced or stopped. Amedication media is delivered through the media delivery port 26 andultrasound energy 40 is delivered from the ultrasound assembly 12. Theultrasound energy 40 can be delivered from the ultrasound assembly 12before, after, during or intermittently with the delivery of the mediaThe occlusion of the vessel 34 before the delivery of the media canserve to prevent the media from being swept from the tissue site 32 bythe fluid flow.

In each of the FIGS. 9A-91 illustrated above, the media can besystemically delivered. The catheter 10 is positioned adjacent to thetissue site before, after or during the systemic administration of themedia When the media includes microbubbles which must be burst beforetheir therapeutic effect can be obtained, the ultrasound energy can bedelivered after the microbubbles have had sufficient time to reach thedesired tissue site in sufficient concentrations. A level of ultrasoundwhich ruptures the microbubbles is then delivered from the ultrasoundassembly. After rupture of the microbubbles, the delivery of ultrasoundenergy can be stopped to provide the light activated drug or othertherapeutic time to penetrate the tissue site. The delivery of theultrasound energy can also be continuous to maximize the number ofmicrobubbles which are burst.

When the media is systemically delivered and the light activated drug isincluded in media which does not require an ultrasound activatedrelease, the behavior of the light activated drug within the patientmust be taken into consideration. As described above, many light drugssuch as the macrocycles, initially disperse throughout the body andwhere they are taken up by most tissues. After a period of time, usuallybetween 3 and 48 hours, the drug clears from most normal tissue and isretained to a greater degree in lipid rich regions such as the liver,kidney, tumor and atheroma. As a result, when the tissue site is not alipid rich region, the ultrasound energy should be delivered to thetissue site within 3 to 48 hours of systemically administering themedia. However, when the tissue site is lipid rich, improved results canbe achieved by waiting 3 to 48 hours after systemic administration ofthe media before delivering the ultrasound energy.

FIG. 10A provides a cross section of an ultrasound assembly whichreduces transmission of ultrasound energy from the ultrasound transducerinto the catheter. The ultrasound assembly 12 includes a support member44. Suitable support members 44 include, but are not limited to,polyimide, polyester and nylon. The support member 44 can be attached tothe ultrasound transducer 20. Suitable means for attaching theultrasound transducer 20 to the support member 44 include, but are notlimited to, adhesive bonding and thermal bonding.

The support member 44 supports the ultrasound transducer 20 at anexternal surface 46 of the elongated body 14 such that a chamber 48 isdefined between the ultrasound transducer 20 and the external surface 46of the elongated body 14. The chamber 48 preferably has a height from0.25-10 μm, more preferably from 0.50-5 μm and most preferably from0.0-1.5 μm. The support member 44 can be supported by supports 50positioned at the ends 52 of the support member 44 as illustrated inFIG. 10A. The supports 50 can be integral with the support member 44 asillustrated in FIG. 10C. The outer coating 18 can serve as the supportsas illustrated in FIG. 10D.

The ends 52 of the support member 44 can extend beyond the ends 54 ofthe ultrasound transducer 20. The supports 50 can be positioned beyondthe ends 54 of the ultrasound transducer 20. As a result, the chamber 48can extend along the longitudinal length 56 of the ultrasound transducer20, maximizing the portion of the ultrasound transducer 20 which isadjacent to the chamber 48. The chamber 48 can be filled with a mediumwhich absorbs ultrasound energy or which prevents transmission ofultrasound energy. Suitable gaseous media for filling the chamber 48include, but are not limited to, helium, argon, air and nitrogen.Suitable media for filling the chamber 48 include, but are not limitedto, silicon and rubber. The chamber 48 can also be evacuated. Suitablepressures for an evacuated chamber 48 include, but are not limited to,negative pressures to −760 mm Hg.

The ultrasound assembly can include a second ultrasound transducer 20Aas illustrated in FIGS. 11A-11H. In FIGS. 11A-11C one ultrasoundtransducer encircles the other and in FIGS. 11D-11H the ultrasoundtransducers are longitudinally adjacent to one another. The ultrasoundtransducers 20, 20A can be in contact with one another as illustrated inFIGS. 11A, 11E and 11H or separated from one another as illustrated inFIGS. 11B-11D, 11F and 11G. A single chamber 54 can be defined betweenthe ultrasound transducers 20, 20A and the external surface 46 of theelongated body 14 as illustrated in FIGS. 11C, 11F and 11G or adifferent chamber can be defined between each of the ultrasoundtransducers 20, 20A and the external surface 46. Although the ultrasoundtransducers 20, 20A in FIGS. 11A-11C are illustrated as having the samelongitudinal length, the longitudinal length may be different.

In FIGS. 11A-11H, the different temperature sensors can be positionedadjacent to different ultrasound transducers 20, 20A. As a result, thetemperature adjacent to different ultrasound transducers 20, 20A can bedetected and the level of ultrasound energy produced by each ultrasoundtransducer adjusted in response to the detected temperature.

When the ultrasound assembly includes a second transducer 20A, thetransducers 20, 20A may be constructed from the same or differentmaterials. Both transducers 20, 20A may be configured to radiateultrasound energy in the same direction. Further, one transducer may beconfigured to transmit ultrasound energy in a radial direction and theother in a longitudinal direction in order to increase the angularspectrum over which ultrasound energy can be simultaneously transmitted.The ultrasound transducers can be configured to transmit ultrasoundenergy having the same or different characteristics. The transmission ofultrasound energy with different characteristics allows the sameultrasound assemblies e used to perform different functions. Forinstance, one ultrasound transducer can transmit a frequency which isappropriate for activating a light activated drug while the secondultrasound transducer transmits a frequency appropriate for enhancingpenetration of a therapeutic agent into the treatment site. Thetransducers can be independently or simultaneously. When the transducersare operated simultaneously, the ultrasound assembly produces a waveformwhich is more complex than a single ultrasound transducer. More complexwaveforms can provide advantages such as more efficient rupture ofmicrobubbles. It is also contemplated that the ultrasound assembly caninclude three or more ultrasound transducers arranged similar to thetransducers illustrated in FIGS. 11A-11H.

The ultrasound assembly 12 can be a separate module 58 as illustrated inFIGS. 12A-12B. In FIG. 12A, the catheter 10 includes a first cathetercomponent 60 a second catheter component 62 and an ultrasound assemblymodule 58. The first and second catheter components 60, 62 includecomponent ends 64 which are complementary to the ultrasound assemblymodule ends 66. The component ends 64 can be coupled with the ultrasoundassembly module ends 66 as illustrated in FIG. 12B. Suitable means forcoupling the component ends 64 and the ultrasound assembly module ends66 include, but are not limited to, adhesive, mechanical and thermalmethods. The ultrasound assembly 12 can be integral with the catheter 10as illustrated in FIG. 12C. Further, the outer coating 18 can have adiameter which is larger than the diameter of the elongated body 14 asillustrated in FIG. 10A or can be flush with the external surface 46 ofthe elongated body 14 as illustrated in FIGS. 12A-12C.

The ultrasound assembly 12 can be electrically coupled to produce radialvibrations of the ultrasound transducer 20 as illustrated in FIGS.13A-13B. A first line 68 is coupled with an outer surface 70 of theultrasound transducer 20 while a second line 72 is coupled with an innersurface 74 of the ultrasound transducer 20. The first and second lines68, 72 can pass proximally through the utility lumen 16 as illustratedin FIG. 13A. Alternatively, the first and second lines 68, 72 can passproximally through line lumens 76 within The catheter 10 as illustratedin FIG. 13B. Suitable lines for the ultrasound transducer 20 include,but are not limited to, copper, gold and aluminum. Suitable frequenciesfor the ultrasound energy delivered by the ultrasound transducer 20include, but are not limited to, 20 KHz to 2 MHz.

The ultrasound assembly 12 can be electrically coupled to producelongitudinal vibrations of the ultrasound transducer 20 as illustratedin FIGS. 13C-13D. A first line 68 is coupled with a first end 78 of theultrasound transducer 20 while a second line 72 is coupled with a secondend 80 of the ultrasound transducer 20. The distal portion 82 of thesecond line 72 can pass through the outer coating 18 as illustrated inFIG. 13C. Alternatively, the distal portion 82 of the second line 72 canpass through line lumens 76 in the catheter 10 as illustrated in FIG.13D. As discussed above, the first and second lines 68, 72 can passproximally through the utility lumen 16.

As discussed above, the catheter 10 can include a plurality ofultrasound assemblies. When the catheter 10 includes a plurality ofultrasound assemblies, each ultrasound transducer 20 can each beindividually powered. When the elongated body 14 includes N ultrasoundtransducers 20, the elongated body 14 must include 2N lines toindividually power N ultrasound transducers 20. The individualultrasound transducers 20 can also be electrically coupled in serial orin parallel as illustrated in FIGS. 14A-14B. These arrangements permitmaximum flexibility as they require only 2 lines. Each of the ultrasoundtransducers 20 receive power simultaneously whether the ultrasoundtransducers 20 are in series or in parallel. When the ultrasoundtransducers 20 are in series, less current is required to produce thesame power from each ultrasound transducer 20 than when the ultrasoundtransducers 20 are connected in parallel. The reduced current allowssmaller lines to be used to provide power to the ultrasound transducers20 and accordingly increases the flexibility of the elongated body 14.When the ultrasound transducers 20 are connected in parallel, anultrasound transducer 20 can break down and the remaining ultrasoundtransducers 20 will continue to operate.

As illustrated in FIG. 14C, a common line 84 can provide power to eachultrasound transducer 20 while each ultrasound transducer 20 has its ownreturn line 86. A particular ultrasound transducer 20 can beindividually activated by closing a switch 88 to complete a circuitbetween the common line 84 and the particular ultrasound transducer's 20return line 86. Once a switch 88 corresponding to a particularultrasound transducer 20 has been closed, the amount of power suppliedto the ultrasound transducer 20 can be adjusted with the correspondingpotentiometer 90. Accordingly, an catheter 10 with N ultrasoundtransducers 20 requires only N+1 lines and still permits independentcontrol of the ultrasound transducers 20. This reduced number of linesincreases the flexibility of the catheter 10. To improve the flexibilityof the catheter 10, the individual return lines 86 can have diameterswhich are smaller than the common line 84 diameter. For instance, in anembodiment where N ultrasound transducers 20 will be poweredsimultaneously, the diameter of the individual return lines 86 can bethe square root of N times smaller than the diameter of the common line84.

As discussed above, the ultrasound assembly 12 can include at least onetemperature sensor 22. Suitable temperature sensors 22 include, but arenot limited to, thermistors, thermocouples, resistance temperaturedetectors (RTD)s, and fiber optic temperature sensors 22 which usethermalchromic liquid crystals. Suitable temperature sensor geometriesinclude, but are not limited to, a point, patch, stripe and a bandencircling the ultrasound transducer 20.

When the ultrasound assembly 12 includes a plurality of temperaturesensors 22, the temperature sensors 22 can be electrically connected asillustrated in FIG. 15. Each temperature sensor 22 can be coupled with acommon line 84 and then include its own return line 86. Accordingly, N+1lines can be used to independently sense the temperature at thetemperature sensors 22 when N temperature sensors 22 are employed. Asuitable common line 84 can be constructed from Constantine and suitablereturn lines 86 can be constructed from copper. The temperature at aparticular temperature sensor 22 can be determined by closing a switch88 to complete a circuit between the thermocouple's return line 86 andthe common line 84. When the temperature sensors 22 are thermocouples,the temperature can be calculated from the voltage in the circuit. Toimprove the flexibility of the catheter 10, the individual return lines86 can have diameters which are smaller than the common line 84diameter.

Each temperature sensor 22 can also be independently electricallycoupled. Employing N independently electrically coupled temperaturesensors 22 requires 2N lines to pass the length of the catheter 10.

The catheter 10 flexibility can also be improved by using fiber opticbased temperature sensors 22. The flexibility can be improved becauseonly N fiber optics need to be employed sense the temperature at Ntemperature sensors 22.

The catheter 10 can be coupled with a feedback control system asillustrated in FIG. 16. The temperature at each temperature sensor 22 ismonitored and the output. power of a energy source adjusted accordingly.The physician can, if desired, override the closed or open loop system.

The feedback control system includes an energy source 92, power circuits94 and a power calculation device 96 coupled with each ultrasoundtransducer 20. A temperature measurement device 98 is coupled with thetemperature sensors 22 on the catheter 10. A processing unit 100 iscoupled with the power calculation device 96, the power circuits 94 anda user interface and display 102.

In operation, the temperature at each temperature sensor 22 isdetermined at the temperature measurement device 98. The processing unit100 receive so signals indicating the determined temperatures from thetemperature measurement device 98. The determined temperatures can thenbe displayed to the user at the user interface and display 102.

The processing unit 100 includes logic for generating a temperaturecontrol signal. The temperature control signal is proportional to thedifference between the measured temperature and a desired temperature.The desired temperature can be determined by the user. The user can setthe predetermined temperature at the user interface and display 102.

The temperature control signal is received by the power circuits 94. Thepower circuits 94 adjust the power level of the energy supplied to theultrasound transducers 20 from the energy source 92. For instance, whenthe temperature control signal is above a particular level, the powersupplied to a particular ultrasound transducer 20 is reduced inproportion to the magnitude of the temperature control signal.Similarly, when the temperature control signal is below a particularlevel, the power supplied to a particular ultrasound transducer 20 isincreased in proportion to the magnitude of the temperature controlsignal. After each power adjustment, the processing unit 100 monitorsthe temperature sensors 22 and produces another temperature controlsignal which is received by the power circuits 94.

The processing unit 100 can also include safety control logic. Thesafety control logic detects when the temperature at a temperaturesensor 22 has exceeded a safety threshold. The processing unit 100 canthen provide a temperature control signal which causes the powercircuits 94 to stop the delivery of energy from the energy source 92 tothe ultrasound transducers 20.

The processing unit 100 also receives a power signal from the powercalculation device 96. The power signal can be used to determine thepower being received by each ultrasound transducer 20. The determinedpower can then be displayed to the user on the user interface anddisplay 102.

The feedback control system can maintain the tissue adjacent to theultrasound transducers 20 within a desired temperature range for aselected period of time. As described above, the ultrasound transducers20 can be electrically connected so each ultrasound transducer 20 cangenerate an independent output. The output maintains a selected energyat each ultrasound transducer 20 for a selected length of time.

The processing unit 100 can be a digital or analog controller, or acomputer with software. When the processing unit 100 is a computer itcan include a CPU coupled through a system bus. The user interface anddisplay 102 can be a mouse, keyboard, a disk drive, or othernon-volatile memory systems, a display monitor, and other peripherals,as are known in the art. Also coupled to the bus is a program memory anda data memory.

In lieu of the series of power adjustments described above, a profile ofthe power delivered to each ultrasound transducer 20 can be incorporatedin the processing unit 100 and a preset amount of energy to be deliveredmay also be profiled. The power delivered to each ultrasound transducer20 can then be adjusted according to the profiles.

The above catheters are suitable for locally delivering a mediaincluding a light activated drug. Suitable light activated drugsinclude, but are not limited to, fluorescein, merocyanin. However,preferred light activated drugs include xanthene and its derivatives andthe photoreactive pyrrole-derived macrocycles and their derivatives dueto a reduced toxicity and an increased biological affinity. Suitablephotoreactive pyrrole-derived macrocycles include, but are not limitedto, naturally occurring or synthetic porphyrins, naturally occurring orsynthetic chlorins, naturally occurring or synthetic bacteriochlorins,synthetic isobateriochlorins, phthalocyanines, naphtalocyanines, andexpanded pyrrole-based macrocyclic systems such as porphycenes,sapphyrins, and texaphyrins. Examples of suitable pyrrole-basedmacrocyclic classes are illustrated in FIGS. 17A-N.

As described above, the derivative of the pyrrole-based macrocycleclasses can be used. For the purposes of illustrating some of thederivatives a macrocycle class, FIG. 17B-2 illustrates a formula for thederivatives of texaphyrin: where M is H, CH₃, a divalent metal cationselected from the group consisting of Ca(II), Mn(II), Co(II), Ni(II),Zn(II), Cd(II), Hg(II), Fe(II), Sm(II), and UO(II) or a trivalent metalcation selected from the group consisting of Mn(III), Co(III), Ni(III),Fe(III), Ho(III), Ce(III), Y(III), In(III), Pr(III), Nd(III), Sm(III),Eu(III), Gd(III), Tb(III), Dy(III), Er(III), Tm(III), Yb(III), Lu(III),La(III), and U(III). Preferred metals include Lu(III), Dy(III), Eu(III),or Gd(III). M may be H or CH₃ in a non-metalated form of texaphyrin. R₁,R₂, R₃, R₄, R₅ and R₆ can independently be hydrogen, hydroxyl, alkyl,hydroxyalkyl, alkoxy, hydroxyalkoxy, saccharide, carboxyalkyl,carboxyamidealkyl, a site-directing molecule, or a linker to asite-directing molecule where at least one of R₁, R₂, R₃, R₄, R₅ and R₆is hydroxyl, hydroxyalkoxy, saccharide, alkoxy, carboxyalkyl,carboxyamidealkyl, hydroxyalkyl, a site-directing molecule or a coupleto a site-directing molecule; and N is an integer less than or equal to2.

A preferred paramagnetic metal complex is the Gd(III) complex of4,5-diethyl-10,23-dimethyl-9,24-bis(3-hydroxypropyl)-16,17-bis[2-(2-methoxyethoxy)ethoxy]ethoxy-13,20,25,26,27-pentaazapentacyclo[20.2.1.1^(3.6).1^(8.11).0^(14.19)]heptacosa-1,3,5,7,9,11(27),12,14(19),15,17,20,22(25),23-tridecaene (“GdT2BET”) and a preferreddiamagnetic metal complex is the Lu(III) complex of4,5-diethyl-10,23-dimethyl-9,24-bis(3-hydroxypropyl)-16,17-bis[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]-13,20,25,26,27-pentaazapentacyclo[20.2.1.1^(3.6).1⁸¹¹.0^(14.19)]heptacosa-1,3,5,7,9,11(27),12,14(19),15,17,20,22(25),23-tridecaene(“LuT2BET”).

R₁, R₂, R₃, R₄, R₆ and may also independently be amino, carboxy,carboxamide, ester, amide sulfonato, aminoalkyl, sulfonatoalkyl,amidealkyl, aryl, etheramide or equivalent formulae conferring thedesired properties. In a preferred embodiment, at least one of R₁, R₂,R₃, R₄, R₅ and R₆ is a site-directing molecule or is a couple to asite-directing molecule. For bulky R groups on the benzene ring portionof the molecule such as oligonucleotides, one skilled in the art wouldrealize that derivatization at one position on the benzene potion ismore preferred.

Hydroxyalkyl means alkyl groups having hydroxyl groups attached. Alkoxymeans alkyl groups attached to an oxygen. Hydroxyalkoxy means alkylgroups having ether or ester linkages, hydroxyl groups, substitutedhydroxyl groups, carboxyl groups, substituted carboxyl groups or thelike. Saccharide includes oxidized, reduced or substituted saccharide;hexoses such as D-glucose, D-mannose or D-galactose; pentoses such asD-ribose or D-arabinose; ketoses such as D-ribulose or D-fructose;disaccharides such as sucrose, lactose, or maltose; derivatives such asacetals, amines, and phosphorylated sugars; oligosacchrides, as well asopen chain forms of various sugars, and the like. Examples ofamine-derivatized sugars are galactosamine, glucosamine, and sialicacid. Carboxyamidealkyl means alkyl groups with secondary or tertiaryamide linkages or the like. Carboxyalkyl means alkyl groups havinghydroxyl groups, carboxyl or amide substituted ethers, ester linkages,tertiary amide linkages removed from the ether or the like.

For the above-described texaphyrins, hydroxyalkoxy may be alkyl havingindependently hydroxy substituents and ether branches or may beC_((n−x))H_(((2n+1)−2x))O_(x)O_(y) or OC_((n−x))H_((2n+2)−2x))O_(x)O^(y)where n is a positive integer from 1 to 10, x is zero or a positiveinteger less than or equal to n, and y is zero or a positive integerless than or equal to ((2n+1)−2x). The hydroxyalkoxy or saccharide maybe C_(n)H_(((2n+1)−q))O_(y)R^(a) _(q), OC_(n)H_((2n+1)−q)O) _(y)R^(a)_(q) or (CH₂)_(n)CO₂R^(a) where n is a positive integer from 1 to 10, yis zero or a positive integer less than ((2n+1)−q), q is zero or apositive integer less than or equal to 2n+1, and R^(a) is independentlyH, alkyl, hydroxyalkyl, saccharide, C_((m−w))H_(((2m+1)−2w))O_(w)O_(z),O₂CC_((m−w))H_(((2m+1)−2w))O_(w)O_(z) orN(R)OCC_((m−w))H_(((2m+1)−2w))O_(w)O_(z). In this case, m is a positiveinteger from 1 to 10, w is zero or a positive integer less than or equalto m, z is zero or a positive integer less than or equal to ((2m+1)−2w),and R is H, alkyl, hydroxyalkyl, or C_(m)H_((2m+1)−r))O_(z)R^(b) _(r)where m is a positive integer from 1 to 10, z is zero or a positiveinteger less than ((2m+1)−r), r is zero or a positive integer less thanor equal to 2m+1, and R^(b) is independently H, alkyl, hydroxyalkyl, orsaccharide.

Carboxyamidealkyl may be alkyl having secondary or tertiary amidelinkages or (CH₂)_(n)CONHR^(a), O(CH₂)_(n)CONHR^(a),(CH₂)_(n)CON(R^(a))2, or O(CH₂)_(n)CON(R^(a))2 where n is a positiveinteger from 1 to 10, and R is independently H, alkyl, hydroxyalkyl,saccharide, C_((m−w))H_(((2m+1)−2w))O_(w)O_(z),O₂CC_((m−w))H_(((2m+1)−2w))O_(w)O_(z),N(R)OCC_((m−w))H_(((2m+1)−2w))O_(w)O_(z), or site-directing molecule. Inthis case, m is a positive integer from 1 to 10, w is zero or a positiveinteger less than or equal to ((2M+1)−2w), and R is H, alkyl,hydroxyalkyl, or C_(m)H_(((2m+1)−r))O_(z)R^(b) _(r). In this case, m isa positive integer from 1 to 10, w is zero or a positive integer lessthan or equal to m, z is zero or a positive integer less than or equalto ((2M+1)−r), r is zero or a positive integer less than or equal to2m+1, and R^(b) is independently H, alkyl, hydroxyalkyl, or saccharide.In a preferred embodiment, R^(a) is an oligonucleotide.

Carboxyalkyl may be alkyl having a carboxyl substituted ether, an amidesubstituted ether or a tertiary amide removed from an ether orC_(n)H_((2n+1)−q))O_(y)R^(c) _(q) or OC_(n)H_((2n+1))−q))O_(y)R^(e) _(q)where n is a positive integer from 1 to 10; y is zero or a positiveinteger less than ((2n+1)−q), q is zero or a positive integer less thanor equal to 2n+1, and R^(c) is (CH₂)_(n)CO₂R^(d), (CH₂)_(n)COHR^(d),(CH₂)_(n)CON(R^(d))₂ or a site -directing molecule. In this case, n is apositive integer from 1 to 10, R^(d) is independently H, alkyl,hydroxyalkyl, saccharide, C_((m−w))H_(((2m+1)−2w))O_(w)O_(z),O₂CC_((m−w))H_(((2m+1)−2w))O_(w)O_(z) orN(R)OCC_((m−w))H_((2m+1)−2w))O_(w)O_(z). In this case, m is a positiveinteger from 1 to 10, z is zero or a positive integer less than((2m+1)−2w), and R is H, alkyl, hydroxyalkyl, orC_(m)H_(((2m+1)−r))O_(z)R^(b) _(r). In this case, m is-a positiveinteger from 1 to 10 , z is zero or a positive integer less than((2m+1)−r), r is zero or a positive integer less than or equal to 2M+1,and R^(b) is independently H, alkyl, hydroxyalkyl, or saccharide. In apreferred embodiment, R^(c) is an oligonucleotide.

Exemplary texaphyrins are listed in Table 1.

TABLE 1 Representative Substitutes for Texaphyrin Macrocycles TXP R₁ R₂R₃ R₄ R₅ R₆ A1 CH₂(CH₂)₂OH CH₂H₃ CH₂CH₃ CH₃ O(CH₂)₃OH O(CH2)3OH A2 ″ ″ ″″ O(CH₂CH₂O)₃CH₃ O(CH₂CH₂O)₃CH₃ A3 ″ ″ ″ ″ O(CH₂)_(n)CON— ″ linker-site-directing molecule, n = 1-7 A4 ″ ″ ″ ″ O(CH₂)_(n)CON— H linker-site-directing molecule A5 ″ ″ ″ ″ OCH₂CO-hormone ″ A6 ″ ″ ″ ″ O(CH₂CH₂O)₃CH₃″ A7 ″ ″ ″ ″ OCH₂CON-linker- O(CH₂CH₂O)₃CH₃ site-directing molecule A8 ″″ ″ ″ OCH₂CO-hormone ″ A9 ″ ″ ″ ″ O(CH₂CH₂O)₁₂₀CH₃ O(CH₂CH₂O)₃CH₂—CH₂—N-imidazole A10 ″ ″ ″ ″ saccharide H A11 ″ ″ ″ ″ OCH₂CON— ″(CH₂CH₂OH)₂ A12 ″ ″ ″ ″ CH₂CON(CH₃)CH₂— ″ (CHOH)₄CH₂OH A13 ″ COOH COOH ″CH₂CON(CH₃)CH₂— ″ (CHOH)₄CH₂OH A14 ″ COOCH₂CH₃ COOCH₂CH₃ ″CH₂CON(CH₃)CH₂— ″ (CHOH)₄CH₂OH A15 Ch₂CH₂CON(CH₂CH₂OH)₂ CH₂H₃ CH₂CH₃ ″CH₂CON(CH₂)CH₂— ″ (CHOH)₄CH₂OH A16 CH₂CH₂ON(CH₃)CH₂— ″ ″ ″ OCH₃ OCH₃(CHOH)₄CH₂OH A17 CH₂(CH₂)₂OH ″ ″ ″ O(CH₂)_(n)COOH, n = 1-7 H A18 ″ ″ ″ ″(CH₂)_(n)—CON— ″ linker-site-directing molecule, n = 1-7 A19 ″ ″ ″ ″YCOCH₂-linker- ″ site-directing molecule Y = NH, O A20 CH₂H₃ CH₃CH₂CH₂COOH ″ O(CH₂)₂CH₂OH O(CH₂)₂CH₂OH A21 ″ ″ CH₂CH₂CON-oligo ″ ″ ″ A22CH₂(CH₂)₂OH CH₂CH₃ CH₂CH₃ ″ O(CH₂)₂CO-histamine H

Preferred pyrrole-based macrocycles include, but are not limited to thehydro-monobenzoporphyrins (the so-called “fi porphyrine” or “Gp”compounds) disclosed in U.S. Pat. Nos. 4,920,143 and 4,883,790 which areincorporated herein by reference. Typically, these compounds are poorlywater-soluble (less than 1 mg/ml) or water-insoluble. Gp is preferablyselected from the group consisting of those compounds having one of theformulae A-F set forth in FIGS. 18A-F, mixtures thereof, and themetalated and labeled forms thereof.

In FIGS. 18A-F, R¹ and R² can be independently selected from the groupconsisting of carbalkoxy (2-6C), alkyl (1-6C) sulfonyl, aryl (6-10C),sulfonyl, aryl (6-10C), cyano, and —CONR⁵CO— wherein R⁵ is aryl (6-10C)or alkyl (1-6C). Preferably, however, each of R¹ and R² is carbalkoxy(2-6C). R³ can be independently carboxyalkyl (2-6C) or a salt, amide,ester or acylhydrazone thereof, or is alkyl (1-6C). Preferably R³ is—CH²CH²COOH or a salt, amide, ester or acylhydrazone thereof.

R⁴ is —CHCH₂; —CHOR^(4′) wherein R^(4′) is H or alkyl (1-6C), optionallysubstituted with a hydrophilic substituent; —CHO; —COOR^(4′);CH(OR^(4′))CH₃; CH(OR^(4′))CH₂OR^(4′); —(SR^(′′))CH₃; —CHNR^(4′) ₂)CH₃;—CH(CN)CH₃; —CH(COOR^(4′))CH₃; —CH(OOCR^(4′))CH₃; CH(halo)CH₃;—CH(halo)CH₂(halo); an organic group of <12C resulting from direct orindirect derivatization of a vinyl group; or R⁴ consists of 1-3tetrapyrrole-type nuclei of the formula —L—P, wherein —L— is selectedfrom the group consisting of

and P is a second Gp, which is one of the formulae A-F (FIG. 18) butlacks R⁴, or another porphyrin group. When P is another porphyrin group,P preferably has the formula illustrated in FIG. 19: wherein each R isindependently H or lower alkyl (1-4C); two of the four bonds shown asunoccupied on adjacent rings are joined to R³; one of the remainingbonds shown as unoccupied is joined to R⁴; and the other is joined to L;with the proviso that if R⁴ is —CHCH₂, both R³ groups cannot becarbalkoxyethyl. The preparation and use of such compounds is disclosedin U.S. Pat. Nos. 4,920,143 and 4,883,790, which are hereby incorporatedby reference.

Even more preferred for including in liposomes are light activated drugsthat are designated as benzoporphyrin derivatives (“BPD's”). BPD's arehydrolyzed forms, or partially hydrolyzed forms, of the rearrangedproducts of formula A-C or formula A-D, where one or both of theprotected carboxyl groups of R³ are hydrolyzed. Particularly preferredis the compound referred to as BPD-MA in FIGS. 20A-D, which has twoequally active regioisomers.

As described above, activating a light activated drug included in amicrobubble can enhance rupture of the microbubble. Preferred lightactivated drugs for including in a microbubble to enhance rupture of themicrobubble include Hematporphyrin, Rose Bengal, Eosin Y, Erythrocin,Rhodamine B, and PHOTOFRIN. The formulae for these preferred lightactivated drugs are illustrated in FIGS. 21A-B where Rose Bengal, EosinY, Erythrocin and Rhodamine B are xanthene derivatives.

As discussed above, the light activated drug can be coupled with a sitedirecting molecule to form a light activated drug conjugate. Suitablesite-directing molecules include, but are not limited to:polydeoxyribonucleotides, oligodeoxyribonucleotides, polyribonucleotideanalogs, oligoribonucleotide analogs; polyamides including peptideshaving an affinity for a biological receptor and proteins such asantibodies; steroids and steroid derivatives; hormones such as estradiolor histamine; hormone mimics such as morphine and further macrocyclessuch as sapphyrins and rubyrins. It is understood that the terms“nucleotide”, “polynucleotide”, and “oligonucleotide”, as used hereinand in the appended claims, refer to both naturally occurring andsynthetic nucleotides, poly- and oligonucleotides and to analogs andderivatives thereof such as methylphosphonates, phosphotriesters,phosphorothioates, and phosphoramidates and the like.Deoxyribonucleotides and ribonucleotide analogs are contemplated assite-directing molecules.

When the site-directing molecule is an oligonucleotide, theoligonucleotide may be derivatized at the bases, the sugars, the end ofthe chains, or at the phosphate groups of the backbone to promote invivo stability. Modifications of the phosphate groups are preferred inone embodiment since phosphate linkages are sensitive to nucleaseactivity. Preferred derivatives are the methylphosphonates,phosphotriesters, phosphorothioates, and phosphoramidates. Additionally,the phosphate linkages may be completely substituted with non-phosphatelinkages such as amide linkages. Appendages to the ends of theoligonucleotide chains also provide exonuclease resistance. Sugarmodifications may include alkyl groups attached to an oxygen of a ribosemoiety in a ribonucleotide. In particular, the alkyl group is preferablya methyl group and the methyl group is attached to the 2′ oxygen of theribose. Other alkyl groups may be ethyl or propyl.

A linker may be used to couple the light activated drug with the sitedirecting molecule. Exemplary linkers include, but are not limited to,amides, amine, thioether, ether, or phosphate covalent bonds asdescribed in the examples for attachment of oligonucleotides. In apreferred embodiment, an oligonucleotide or other site-directingmolecules is covalently bonded to a texaphyrin or other light activateddrugs via a carbon-nitrogen, carbon-sulfur, or a carbon-oxygen bond.

As described above, the media can be an emulsion which includes a lightactivated drug. The emulsions described below are suitable for deliveryinto a body since they avoid pharmaceutically undesirable organicsolvents, solubilizers, oils or emulsifiers. A wide range of lightactivated drug concentrations can be used in the emulsion. Suitableconcentrations of light activated drug within the emulsion include, butare not limited to, approximately 0.01 to 1 gram/100 ml, preferablyabout 0.05 to about 0.5 gram/100 ml, and approximately 0.1 g/100 ml.

The emulsion includes a lipoid as a hydrophobic component dispersed in ahydrophilic phase. The hydrophobic component of the emulsion comprises apharmaceutically acceptable triglyceride, such as an oil or fat of avegetable or animal nature, and preferably is selected from the groupconsisting of soybean oil, safflower oil, marine oil, black current seedoil, borage oil, palm kernel oil, cotton seed oil, corn oil, sunflowerseed oil, olive oil or coconut oil. Physical mixtures of oils and/orinteresterfied mixtures can be employed. The preferred oils are mediumchain length triglycerides having C₈-C₁₀ chain length and morepreferably saturated. The preferred triglyceride is a distillateobtained from coconut oil. The hydrophobic content of the emulsion ispreferably approximately 5 to 50 g/100 ml, more preferably about 10 toabout 30 g/100 ml and approximately 20 g/100 ml of the emulsion.

The emulsion can also contains a stabilizer such as phosphatides,soybean phospholipids, nonionic block copolymers of polyoxethylene andpolyoxpropylene (e.g. poloxamers), synthetic or semi-syntheticphospholipids, and the like. The preferred stabilizer is purified eggyolk phospholipid. The stabilizer is usually present in the compositionin amounts of about 0.1 to about 10, and preferably about 0.3 to about 3grams/100 ml, a typical example being about 1.5 grams/100 ml.

The emulsion can also include one or more bile acids salts as acostablizer. The salts are pharmacologically acceptable salts of bileacids selected from the group of cholic acid, deoxycholic acid andgylcocholic acid, and preferably of cholic acid. The salts are typicallyalkaline metal or alkaline earth metal salts and preferably sodium,potassium, calcium or magnesium salts, and most preferably, sodiumsalts. Mixtures of bile acid salts can be employed if desired. Theamount of bile acid salt employed is usually about 0.01 to about 1.0 andpreferably about 0.05 to about 0.4 grams/100 ml, a typical example beingabout 0.2 grams/100 ml.

Suitable pH for the emulsion includes, but is not limited toapproximately 7.5 to 9.5, and preferably approximately 8.5. The pH canbe adjusted to the desired value, if necessary, by adding apharmaceutically acceptable base, such as sodium hydroxide, potassiumhydroxide, calcium hydroxide, magnesium hydroxide and ammoniumhydroxide.

Water can be added to the emulsion to achieve the desired concentrationof various components within the emulsion. Further, the emulsion caninclude auxiliary ingredients for regulating the osmotic pressure tomake the emulsion isotonic with the blood. Suitable auxiliaryingredients include, but are not limited to, auxiliary surfactants,isotonic agents, antioxidants, nutritive agents, trace elements andvitamins. Suitable isotonic agents include, but are not limited to,glycerin, amino acids, such as alanine, histidine, glycine, and/or sugaralcohols, such as xylitol, sorbitol and/or mannitol. Suitableconcentrations for isotonic agents within the emulsion include, but arenot limited to, approximately 0.2 to about 8.0 grams/100 ml andpreferably about 0.4 to about 4 grams/100 ml and most preferably 1.5 to2.5 gram/100 ml.

Antioxidants can be used to enhance the stability of the emulsion, atypical example being α-tocopherol. Suitable concentrations for theantioxidants include, but are not limited to approximately 0.005 to 0.5grams/100 ml, approximately 0.02 to about 0.2 grams/100 ml and mostpreferably approximately 0.05 to 0.15 grams/100 ml.

The emulsions can also contain auxiliary solvents, such as an alcohol,such as ethyl alcohol or benzyl alcohol, with ethyl alcohol beingpreferred. When employed, such is typically present in amounts of about0.1 to about 4.0, and preferably about 0.2 to about 2 grams/100 ml, atypical example being about 1 gram/100 ml. The ethanol is advantageoussince it facilitates dissolution of poorly water-soluble light activateddrugs and especially those that form crystals which may be verydifficult to dissolve in the hydrophobic phase. Accordingly, the ethanolmust be added directly to the hydrophobic phase during preparation to beeffective. For maximum effectiveness, the ethanol should constituteabout 5% to 15% by weight of the hydrophobic phase. In particular, ifethanol constitutes less than 5% by weight of the hydrophobic phase,dissolution of the light activated drug can become unacceptably slow.When the ethanol concentration exceeds 15%, large (>5 μm diameter) andpoorly emulsified oil droplets can form in the emulsion. The particlesin the emulsion are preferably less than about 5.0 μm in diameter, morepreferably less than 2.0 μm in diameter and most preferably less than0.5 μm or below.

A typical emulsion is prepared using the following technique. Thetriglyceride oil is heated to 50°-70° C. while sparging with nitrogengas. The required amounts of stabilizer (e.g. egg yolk phospholipids),bile acid salt, alcohol (e.g. ethanol), antioxidant (e.g. α-to-copherol)and light activated drug are added to the triglyceride while processingfor about 5 to about 20 minutes with a high speed blender or overheadmixer to ensure complete dissolution or uniform suspension.

In a separate vessel, the required amounts of water and isotonic agent(e.g.-glycerin) are heated to the above temperature (e.g. 50°-70°) whilesparging with nitrogen gas. Next, the aqueous phase is transferred intothe prepared hydrophobic phase and high speed blending is continued foranother 5 to 10 minutes to produce a uniform but coarse preemulsion (orpremix). This premix is then transferred to a conventional high pressurehomogenizer (APV Gaulin) for emulsification at about 8,000-10,000 psi.The diameter of the dispersed oil droplets in the finished emulsion willbe less than 5 μm, with a large proportion less than 1 μm. The meandiameter of these oil droplets will be less than 1 μm, preferably from0.2 to 0.5 μm. The emulsion product is then filled into borosilicate(Type 1) glass vials which are stoppered, capped and terminally heatsterilized in a rotating steam autoclave at about 121° C.

These emulsions can withstanding autoclaving as well as freezing atabout 0° to −20° C. Such can be stored for a relatively long time withminimal physical and chemical breakdown, i.e. at least 12-18 months at4°-8° C. The vehicle composition employed is chemically inert withrespect to the incorporated pharmacologically active light activateddrug.

The emulsions can exhibit very low toxicity following intravenousadministration and exhibit no venous irritation and no pain oninjection. The emulsions exhibit minimal physical and chemical changes(e.e. formation of non-emulsified surface oil) during controlledshake-testing on a horizontal platform. Moreover, the oil-in-wateremulsions promote desirable pharmacoldnetics and tissue distribution ofthe light activated drug in vivo.

As discussed above, the light activated drug can also be delivered tothe body in a media which includes microbubbles. Suitable substrates forthe microbubble include, but are not limited to, biocompatible polymers,albumins, lipids, sugars or other substances. U.S. Pat. Nos. 5,701,899and 5,578,291 teaches a method for synthesizing microbubbles with asugar and protein substrate and is incorporated herein by reference.U.S. Pat. Nos. 5,665,383 and 5,665, 382 teaches a method forsynthesizing microbubbles with a polymeric substrate and is incorporatedherein by reference. U.S. Pat. Nos. 5,626,833 and 5,798,091 teachmethods for synthesizing microbubbles with a surfactant substrate andare incorporated herein by reference. A preferred microbubble has alipid substrate. U.S. Pat. Nos. 5,772,929 teaches methods forsynthesizing microbubbles with a lipid substrate. U.S. Pat. Nos.5,776,429, 5,715,824 and 5,770,222 teach preferred methods forsynthesizing microbubbles with a lipid substrate and a gas interior andare incorporated herein by reference.

Suitable microbubbles with a lipid substrate can be liposomes. Theliposomes can be unilamellar vesicles having a single membrane bilayeror multilamellar vesicles having multiple membrane bilayers, eachbilayer being separated from the next by an aqueous layer. A liposomebilayer is composed of two lipid monolayers having a hydrophobic “tail”region and a hydrophilic “head” region. The formula of the membranebilayer is such that the hydrophobic (nonpolar) “tails” of the lipidmonolayers orient themselves towards the center of the bilayer, whilethe hydrophilic “heads” orient themselves toward the aqueous phase.Either unilamellar or multilamellar or other types of liposomes may beused.

A hydrophilic light activated drug can be entrapped in the aqueous phaseof the liposome before the drug is delivered into the patient.Alternatively, if the light activated drug is lipophilic, it mayassociate with the lipid bilayer. Liposomes may be used to help “target”the light activated drug to an active site or to solubilize hydrophobiclight activated drugs. Light activated drugs are typically hydrophobicand form stable drug-lipid complexes.

As discussed above, many light activated drugs have low solubility inwater at physiological pH's, but are also insoluble in (1)pharmaceutically acceptable aqueous-organic co-solvents, (2) aqueouspolymeric solutions and (3) surfactant/micellar solutions. However, suchlight activated drugs can still be “solubilized” in a form suitable fordelivery into a body by using a liposome composition. For example, oneexample of a light activated drug BPD-MA (See Formula A of FIG. 20) canbe “solubilized” at a concentration of about 2.0 mg/ml in aqueoussolution using an appropriate mixture of phospholipids to formencapsulating liposomes.

Although the light activated drug can be included in many differenttypes of liposomes, the following description discloses particularliposome compositions and methods for making the liposomes which areknown to be “fast breaking”. In fast breaking liposomes, the lightactivated drug-liposome combination is stable in vitro but, whenadministered in vivo, the light activated drug is rapidly released intothe bloodstream where it can associate with serum lipoproteins. As aresult, the localized delivery of liposomes combined with the fastbreaking nature of the liposomes can result in localization of the lightactivated drug in the tissues near the catheter. Further, the fastbreaking liposomes can prevent the liposomes from leaving the vicinityof the catheter intact and then concentrating in non-targeted tissuessuch as the liver. Delivery of ultrasound energy from the catheter canalso serve to break apart the liposomes after they have been deliveredfrom the catheter.

Liposomes are typically formed spontaneously by adding water to a drylipid film. Liposomes which include light activated drugs can include amixture of the commonly encountered lipids dimyristoyl phosphatidylcholine (“DMPC”) and egg phosphatidyl glycerol (“EPG”). The presence ofDMPC is important because DMPC is the major component in the compositionto form liposomes which can solubilize and encapsulate insoluble lightactivated drugs into a lipid bilayer. The presence of EPG is importantbecause the negatively charged, polar head group of this lipid canprevent aggregation of the liposomes.

Other phospholipids, in addition to DMPC and EPG, may also be present.Examples of suitable additional phospholipids that may also beincorporated into the liposomes include phosphatidyl cholines (PCS),including mixtures of dipalmitoyl phosphatidyl choline (DPPC) anddistearoyl phosphatidyl choline (DSPC). Examples of suitablephosphatidyl glycerols (PGs) include dimyristoyl phosphatidyl glycerol(DMPG), DLPG and the like.

Other types of suitable lipids that may be included are phosphatidylethanolamines (PEs), phosphatidic acids (PAs), phosphatidyl serines, andphosphatidyl inositols.

The molar ratio of the light activated drug to the DMPC/EPG phospholipidmixture can be as low as 1:7.0 or may contain a higher proportion ofphospholipid, such as 1:7.5. Preferably, this molar ratio is 1:8 or morephospholipid, such as 1:10, 1:15, or 1:20. This molar ratio depends uponthe exact light activated drug being used, but will assure the presenceof a sufficient number of DMPC and EPG lipid molecules to form a stablecomplex with many light activated drugs. When the number of lipidmolecules is not sufficient to form a stable complex, the lipophilicphase of the lipid bilayer becomes saturated with light activated drugmolecules. Then, any slight change in the process conditions can forcesome of the previously encapsulated light activated drug to leak out ofthe vesicle, onto the surface of the lipid bilayer, or even out into theaqueous phase.

If the concentration of light activated drug is high enough, it canactually precipitate out from the aqueous layer and promote aggregationof the liposomes. The more unencapsulated light activated drug that ispresent, the higher the degree of aggregation. The more aggregation, thelarger the mean particle size will be, and the more difficult aseptic orsterile filtration will be. As a result, small changes in the molarratio can be important in achieving proper filterability of the liposomecomposition.

Accordingly, slight increases in the lipid content can increasesignificantly the filterability of the liposome composition byincreasing the ability to form and maintain small particles. This isparticularly advantageous when working with significant volumes of 500ml, a liter, five liters, 40 liters, or more, as opposed to smallerbatches of about 100-500 ml or less. This volume effect is thought tooccur because larger homogenizing devices tend to provide less efficientagitation than can be accomplished easily on a small scale. For example,a large size Microfluidizer™ has a less efficient interaction chamberthan that one of a smaller size.

A molar ratio of 1.05:3:5 BPD-MA:EPG:DMPC (i.e., slightly lessphospholipid than 1:8.0 light activated drug:phospholipid) may providemarginally acceptable filterability in small batches of up to 500 ml.However, when larger volumes of the composition are being made, a highermolar ratio of phospholipid provides more assurance of reliable asepticfilterability. Moreover, the substantial potency losses that are commonin scale-up batches, due at least in part to filterability problems, canthus be avoided.

Any cryoprotective agent known to be useful in the art of preparingfreeze-dried formulations, such as di- or polysaccharides or otherbulking agents such as lysine, may be used. Further, isotonic agentstypically added to maintain isomolarity with body fluids may be used. Ina preferred embodiment, a di-saccharide or polysaccharide is used andfunctions both as a cryoprotective agent and as an isotonic agent.

In a particular embodiment, the particular combination of thephospholipids, DMPC and EPG, and a disaccharide or polysaccharide form aliposomal composition having liposomes of a particularly narrow particlesize distribution. When the process of hydrating a lipid film isprolonged, larger liposomes tend to be formed, or the light activateddrug can even begin to precipitate. The addition of a disaccharide orpolysaccharide provides instantaneous hydration and the large surfacearea for depositing a thin film of the drug-phospholipid complex. Thisthin film provides for faster hydration so that, when the liposome isinitially formed by adding the aqueous phase, the liposomes formed areof a smaller and more uniform particle size. This provides significantadvantages in terms of manufacturing ease.

However, it is also possible that, when a saccharide is present in thecomposition, it is added after dry lipid film formation, as a part ofthe aqueous solution used in hydration. In a particularly preferredembodiment, a saccharide is added to the dry lipid film duringhydration.

Disaccharides or polysaccharides are preferred to monosaccharides forthis purpose. To keep the osmotic pressure of the liposome compositionsimilar to that of blood, no more than 4-5% monosaccharides could beadded. In contrast, about 9-10% of a disaccharide can be used withoutgenerating an unacceptable osmotic pressure. The higher amount ofdisaccharide provides for a larger surface area, which results insmaller particle sizes being formed during hydration of the lipid film.

Accordingly, the preferred liposomal composition comprises adisaccharide or polysaccharide, in addition to the light activated drugand the mixture of DMPC and EPG phospholipids. When present, thedisaccharide or polysaccharide is preferably chosen from among the groupconsisting of lactose, trehalose, maltose, maltotriose, palatinose,lactulose or sucrose, with lactose or trehalose being preferred. Evenmore preferably, the liposomes comprise lactose or trehalose.

Also, when present, the disaccharide or polysaccharide is formulated ina preferred ratio of about 10-20 saccharide to 0.5-6.0 DMPC/EPGphospholipid mixture, respectively, even more preferably at a ratio fromabout 10 to 1.5-4.0. In one embodiment, a preferred but not limitingformulation is lactose or trehalose and a mixture of DMPC and EPG in aconcentration ratio of about 10 to 0.94-1.88 to about 0.65-1.30,respectively.

The presence of the disaccharide or polysaccharide in the compositionnot only tends to yield liposomes having extremely small and narrowparticle size ranges, but also provides a liposome composition in whichlight activated drugs, in a particular, may be stably incorporated in anefficient manner, i.e., with an encapsulation efficiency approaching80-100%. Moreover, liposomes made with a saccharide typically exhibitimproved physical and chemical stability, such that they can retain anincorporated light activated drug without leakage upon prolongedstorage, either as a reconstituted liposomal or as a cryodesiccatedpowder.

Other optional ingredients include minor amounts of nontoxic, auxiliarysubstances in the liposomal composition, such as antioxidants, e.g.,butylated hydroxytoluene, alphatocopherol and ascorbyl palmitate; pHbuggering, agents e.g., phosphates, glycine, and the like.

Liposomes containing a light activated drug may be prepared by combiningthe light activated drug and the DMPC and EPG phospholipids (and anyother optional phospholipids or excipients, such as antioxidants) in thepresence of an organic solvent. Suitable organic solvents include anyvolatile organic solvent, such as diethyl ether, acetone, methylenechloride, chloroform, piperidine, piperidine-water mixtures, methanol,tert-butanol, dimethyl sulfoxide, N-methyl-2-pyrrolidone, and mixturesthereof. Preferably, the organic solvent is water-immiscible, such asmethylene chloride, but water immiscibility is not required. In anyevent, the solvent chosen should not only be able to dissolve all of thecomponents of the lipid film, but should also not react with, orotherwise deleteriously affect, these components to any significantdegree.

The organic solvent is then removed from the resulting solution to forma dry lipid film by any known laboratory technique that is notdeleterious to the dry lipid film and the light activated drug.Preferably, the solvent is removed by placing the solution under avacuum until the organic solvent is evaporated. The solid residue is thedry lipid film. The thickness of the lipid film is not critical, butusually varies from about 30 to about 45 mg/cm², depending upon theamount of solid residual and the total area of the glass wall of theflask. Once formed, the film may be stored for an extended period oftime, preferably not more than 4 to 21 days, prior to hydration. Whilethe temperature during a lipid film storage period is also not animportant factor, it is preferably below room temperature, mostpreferably in the range from about −20 to about 4° C.

The dry lipid film is then dispersed in an aqueous solution, preferablycontaining a disaccharide or polysaccharide, and homogenized to form thedesired particle size. Examples of useful aqueous solutions used duringthe hydration step include sterile water, a calcium- and magnesium-free,phosphate-buffered (pH 7.2-7.4) sodium chloride solution; a 9.75% w/vlactose solution; a lactose-saline solution; 5% dextrose solution; orany other physiologically acceptable aqueous solution of one or moreelectrolytes. Preferably, however, the aqueous solution is sterile. Thevolume of aqueous solution used during hydration can vary greatly, butshould not be so great as about 98% nor so small as about 30-40%. Atypical range of useful volumes would be from about 75% to about 95%,preferably about 85% to about 90%.

Upon hydration, coarse liposomes are formed that incorporate atherapeutically effective amount of the light activateddrugs-phospholipid complex. The “therapeutically effective amount” canvary widely, depending on the tissue to be treated and whether it iscoupled to a target-specific ligand, such as an antibody or animmunologically active fragment. It should be noted that the variousparameters used for selective photodynamic therapy are interrelated.Therefore, the therapeutically effective amount should also be adjustedwith respect to other parameters, for example, fluence, irradiance,duration of the light used in photodynanmic therapy, and the timeinterval between administration of the light activated drug and thetherapeutic irradiation. Generally, all of these parameters are adjustedto produce significant damage to tissue deemed undesirable, such asneovascular or tumor tissue, without significant damage to thesurrounding tissue, or to enable the observation of such undesirabletissue without significant damage to the surrounding tissue.

Typically, the therapeutically effective amount is such to produce adose of light activated drug within a range of from about 0.1 to about20 mg/kg, preferably from about 0.15-2.0 mg/kg and, even morepreferably, from about 0.25 to about 0.75 mg/kg. Preferably, the w/vconcentration of the light activated drug in the composition ranges fromabout 0.1 to about 8.0-10.0 g/L. Most preferably, the concentration isabout 2.0 to 2.5 g/L.

The hydration step should take place at a temperature that does notexceed about 30° C., preferably below the glass transition temperatureof the light activated drug-phospholipid complex formed, even morepreferably at room temperature or lower, e.g., 15°-20° C. The glasstransition temperature of the light activated drug-lipid complex can bemeasure by using a differential scanning microcalorimeter.

In accordance with the usual expectation that the aqueous solubility ofa substance should increase as higher temperatures are used, at atemperature around the transition temperature of the complex, the lipidmembrane tends to undergo phase transition from a “solid” gel state to apre-transition state and, finally, to a more “fluid” liquid crystalstate. At these higher temperatures, however, not only does fluidityincrease, but the degree of phase separation and the proportion ofmembrane defects also increases. This results in an increasing degree ofleakage of the light-activated drug from inside the membrane to theinterface and event out into the aqueous phase. Once a significantamount of liposome leakage has occurred, even slight changes in theconditions such as a small drop in temperature, can shift theequilibrium away from aqueous “solubility” in favor of precipitation ofthe light activated drug. Moreover, once the typically water-insolublelight activated drug begins to precipitate, it is not possible tore-encapsulate it when the lipid bilayer. The precipitate is thought tocontribute significantly to filterability problems.

In addition, the usual thickness of a lipid bilayer in the “solid” gelstate (about 47 Å) decreases in the transition to the “liquid”crystalline state to about 37 Å, thus shrinking the entrapped volumeavailable for the light activated drugs to occupy. The smaller “room” isnot capable of containing as great a volume of light activated drug,which can then be squeezed out of the saturated lipid bilayerinterstices. Any two or more liposomes exuding light activated drug mayaggregate together, introducing further difficulties with respect toparticle size reduction and ease of sterile filtration. Moreover, theuse of higher hydration temperatures, such as, for example, about 35° to45° C., can also result in losses of light activated drug potency as thelight activated drug either precipitates or aggregates during asepticfiltration.

The particle sizes of the coarse liposomes first formed in hydration arethen homogenized to a more uniform size, reduced to a smaller sizerange, or both, to about 150 to 300 nm, preferably also at a temperaturethat does not exceed about 30° C., preferably below the glass transitiontemperature of the light activated drug-phospholipid complex formed inthe hydration step, and even more preferably below room temperature ofabout 25° C. Various high-speed agitation devices may be used during thehomogenization step, such as a Microfluidizer™ model 110F; a sonicator,a high-shear mixer; a homogenizer; or a standard laboratory shaker.

It has been found that the homogenization temperature should be at roomtemperature or lower, e.g., 15°-20° C. At higher homogenizationtemperatures, such as about 32°-42° C., the relative filterability ofthe liposome composition may improve initially due to increased fluidityas expected, but then, unexpectedly, tends to decrease with continuingagitation due to increasing particle size.

Preferably, a high pressure device such a Microfluidizer™ is used foragitation. In microfluidization, a great amount of heat is generatedduring the short-period of time during which the fluid passes through ahigh pressure interaction chamber. In the interaction chamber, twostreams of fluid at a high speed collide with each other at a 90° angle.As the nicrofluidization temperature increases, the fluidity of themembrane also increases, which initially makes particle size reductioneasier, as expected. For example, filterability can increase by as muchas four times with the initial few passes through a Microfluidizer™device. The increase in the fluidity of the bilayer membrane promotesparticle size reduction, which makes filtration of the final compositioneasier. In the initial several passes, this increased fluidity mechanismadvantageously dominates the process.

However, as the number of passes and the temperature both increase, moreof the hydrophobic light activated drug molecules are squeezed out ofthe liposomes, increasing the tendency of the liposomes to aggregateinto larger particles. At the point at which the aggregation of vesiclesbegins to dominate the process, the sizes cannot be reduced any further.Surprisingly, particle sizes actually then tend to grow throughaggregation.

For this reason, the homogenization temperature is cooled down to andmaintained at a temperature no greater than room temperature after thecomposition passes through the zone of maximum agitation, e.g., theinteraction chamber of a Microfluidizer™ device. An appropriate coolingsystem can easily be provided for any standard agitation device in whichhomogenization is to take place, e.g., a Microfluidizer™, such as bycirculating cold water into an appropriate cooling jacket around themixing chamber or other zone of maximum turbulence. While the pressureused in such high pressure devices is not critical, pressures from about10,000 to about 16,000 psi are not uncommon.

As a last step, the compositions are preferably aseptically filteredthrough a filter having an extremely small pore size, i.e., 0.22 μm.Filter pressures used during sterile filtration can vary widely,depending on the volume of the composition, the density, thetemperature, the type of filter, the filter pore size, and the particlesize of the liposomes. However, as a guide, a typical set of filtrationconditions would be as follows: filtration pressure of 15-25 psi;filtration load of 0.8 to 1.5 ml/cm²; and filtration temperature ofabout 25° C.

A typical general procedure is described below with additional exemplarydetail:

(1) Sterile filtration of organic solvent through a hydrophobic, 0.22 μmfilter.

(2) Addition of EPG, DMPC, light activated drug, and excipients to thefiltered organic solvent, dissolving both the excipients and the lightactivated drug.

(3) Filtration of the resulting solution through a 0.22 μm hydrophobicfilter.

(4) Transfer of the filtrate to a rotary evaporator apparatus, such asthat commercially available under the name Rotoevaporator™.

(5) Removal of the organic solvent to form a dry lipid film.

(6) Analysis of the lipid film to determine the level of organic solventconcentration.

(7) Preparation of a 10% lactose solution.

(8) Filtration of the lactose solution through a 0.22 μm hydrophilicfilter.

(9) Hydration of the lipid film with a 10% lactose solution to formcoarse liposomes.

(10) Reduction of the particle sizes of the coarse liposomes by passingthem through a Microfluidizer™ three times.

(11) Determination of the reduced particle size distribution ofliposomes.

(12) Aseptic filtration of the liposome composition through a 0.22 μmhydrophilic filter. (Optionally, the solution may first be pre-filteredwith a 5.0 μm prefilter.)

(13) Analysis of light activated drug potency.

(14) Filling of vials with the liposome composition.

(15) Freeze-drying.

Once formulate the liposome composition may be freeze-dried forlong-term storage if desired. For example, BPD-MA, a preferred lightactivated drug, has maintained its potency in a cryodesiccated liposomecomposition for a period of at lest nine months at room temperature, anda shelf life of at least two years has been projected. If thecomposition is freeze dried, may be packed in vials for subsequentreconstitution with a suitable aqueous solution, such as sterile wateror sterile water containing a saccharide and/or other suitableexcipients, prior to administration, for example, by injection.

Preferably, liposomes that are to be freeze-dried are formed upon theaddition of an aqueous vehicle contain a disaccharide or polysaccharideduring hydration. The composition is then collected, placed into vials,freeze-dried, and stored, ideally under refrigeration. The freeze-driedcomposition can then be reconstituted by simply adding water forinjection just prior to administration.

The liposomal composition provides liposomes of a sufficiently small andnarrow particle size that the aseptic filtration of the compositionthrough a 0.22 μm hydrophilic filter can be accomplished efficiently andwith large volumes of 500 ml to a liter or more without significantclogging of the filter. A particularly preferred particle size range isbelow about 300 nm, more preferably below from about 250 nm. Mostpreferably, the particle size is below about 220 nm.

Generally speaking, the concentration of the light activated drugs inthe liposome depends upon the nature of the light activated drug used.When BPD-MA is used for example, the light activated drug is generallyincorporated in the liposomes at a concentration of about 0.10% up to0.5% w/v. If freeze-dried and reconstituted, this would typically yielda reconstituted solution of up to about 5.0 mg/ml light activated drug.

For diagnosis, the light activated drugs incorporated into liposomes maybe used along with, or may be labeled with, a radioisotope or otherdetecting means. If this is the case, the detection means depends on thenature of the label. Scintigraphic labels such as technetium or indiumcan be detected using ex vivo scanners. Specific fluorescent labels canalso be used but, like detection based on fluorescence of the lightactivated drugs themselves, these labels can require prior irradiation.

The methods of preparing various light activated drugs, light activateddrug conjugates, emulsions and microbubbles are described in greaterdetail in the examples below. These examples are readily adapted topreparing analogous light activated drugs, light activated drugconjugates, emulsions and microbubbles by substitutions of appropriatelight activated drugs, site directing molecule, phospholipids, and otheranalogous components. The following examples are being presented todescribe the preferred components, embodiments, utilities and attributesof the media. For example, although BPD-MA is used as the lightactivated drugs in the microbubble (liposome) examples, the invention isnot intended to be limited to this particular light activated drug.

Example 1 describes the synthesis of a preferred texaphyrin derivative.Examples 2-4 describe different light activated drugs conjugated witholigonucleotides as site directing molecules. Examples 5 and 6 describesa synthesis of an emulsion including a light activated drug. Example 7describes preparation of microbubbles which include a light activateddrug.

EXAMPLE 1 Synthesis of Texaphyrin T2BET Metal Complexes

The synthesis of texaphyrins is provided in U.S. Pat. Nos. 4,935,498,5,162,509 and 5,252,720, all incorporated by reference herein. Thepresent example provides the synthesis of a preferred texaphyrin, namedT2BET, having substituents containing ethoxy groups.

Lutetium(III) acetate hydrate can be purchased from Strem Chemicals,Inc. (Newburyport, Mass.), gadolinium(III) acetate tetrahydrate can bepurchased from Aesar/Johnson Matthey (Ward Hill, Mass.) and LZY-54zeolite can be purchased from UOP (Des Plaines, Ill.). Acetone, glacialacetic acid, methanol, ethanol isopropyl alcohol, and n-heptanes can bepurchased from J. T. Baker (Phillipsburg, N.J.). Triethylamine andAmberlite 904 anion exchange resin can be purchased from Aldrich(Milwaukee, Wis.). All chemicals should be ACS grade and used withoutfurther purification.

FIGS. 22A-I illustrate the synthesis of the gadolinium (III) complex of4,5-diethyl-10,23-dimethyl-9,24bis(3-hydroxypropyl)-16,17-bis[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]-pentaazapentacyclo[20.2.1.1^(3,6).I^(8.11).0^(14,19)]heptacosa-1,3,5,7,9,11(27),12,14,16,18,20,22(25),23-tridecaene which is illustrated as Formula I of FIG. 22. The criticalintermediate 1,2-bis[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]-4,5-dinitrobenzene (Formula E) can beprepared according to a three-step synthetic process outlined in FIGS.22A-I. (Note: References to “Formula A,” “Formula B,” etc. relate toFIGS. 22A, 22B, etc.)

Synthesis of triethylene glycol monomethyl ether monotosylate, FormulaB: In an oven dried 12 L three-necked roundbottom flask, equipped with amagnetic stir bar and a 1000 mL pressure-equalizing dropping funnel, asolution of NaOH (440.0 g, 11.0 mol) is added to 1800 mL water and themixture is cooled to approximately 0° C. A solution of triethyleneglycol monomethyl ether, Formula A, (656.84 g, 4.0 mol) in THF (1000 mL)is added. The clear solution is stirred vigorously at 0° C. for 15 minand a solution of tosyl chloride (915.12, 4.8 mol) in THF (2.0 L) addeddropwise over a 1 h period. The reaction mixture is stirred for anadditional 1 h at O° C., and 10% HCl (5.0 L) is added to quench thereaction (to pH 5-7). The two-phase mixture is transferred to a 4 Lseparatory funnel the organic layer removed, and the aqueous layerextracted with t-butylmethyl ether (3×250 mL). The combined organicextracts are washed with brine (2×350 mL), dried (MgSO₄), and evaporatedunder reduced pressure to afford Formula B, 1217.6 g (95%) as a lightcolored oil. This material is taken to the next step without furtherpurification.

Synthesis of 1,2-bis[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]benzene,Formula D: In a dry 5 L round-bottom flask equipped with an overheadstirrer, reflux condenser, and a gas line, K₂CO₃ (439.47 g, 3.18 mol)and MeOH (1800 mL) are combined under an argon atmosphere. To thiswell-stirred suspension, catechol, Formula C, (140.24 g, 1.21 mol) isadded, and the mixture heated to reflux. Formula B (1012.68 g, 3.18 mol)is then added in one portion. The suspension is stirred at reflux for 24h, cooled to room temperature, and filtered through Celite. The pad isrinsed with 500 mL of methanol and the combined filtrates are evaporatedunder reduced pressure. The resulting brown residue is taken up in 10%NaOH (800 mL), and methylene chloride (800 mL) added with stirring. Themixture is transferred to a 2 L separatory funnel, the organic layerremoved and the aqueous layer extracted with methylene chloride (3×350mL). The organic extracts are combined, washed with brine (350 mL),dried (MgSO₄), evaporated under reduced pressure, and the residue driedin vacuo for several hours to yield 485.6 (95%) of1,2-bis[2-[2-(2-methoxyethoxy)ethoxy]ethoxy)benzene (Formula D). ForFormula D: bp. 165°-220° C., (0.2-0.5 mm Hg); FAB MS, M⁺:m/e 402; HRMS,M⁺: 402.2258 (calcd. for C₂₀H₃₄O₈, 402.2253).

Synthesis of1,2-bis[2-[2-methoxy-ethoxy)ethoxy]ethoxy]-4,5-dinitrobenzene, FormulaE: In an oven dried 1 roundbottom flask Formula D (104 g, 0.26 mol) andglacial acetic acid (120 mL) are combined and cooled to 5° C. To thiswell stirred solution, concentrated nitric acid (80 mL) is addeddropwise over 15-20 min. The temperature of the mixture is held below40° C. by cooling and proper regulation of the rate of addition of theacid. After addition, the reaction is allowed to stir for an additional10-15 min and is then cooled to 0° C. Fuming nitric acid (260 mL) isadded dropwise over 30 min while the temperature of the solution is heldbelow 30° C. After the addition is complete, the red colored solution isallowed to stir at room temperature until the reaction is complete (ca 5h, TLC: 95/5; CH₂Cl₂/MeOH) and then poured into well stirred ice water(1500 mL). Methylene chloride (400 mL) is added, the two-phase mixturetransferred to a 2 L separatory funnel and the organic layer removed.The aqueous layer is extracted with CH2C12 (2×15O mL) and the combinedorganic extracts washed with 10% NaOH (2×250 mL) and brine (250 mL),dried (MgSO₄), and concentrated under reduced pressure. The resultingorange oil is dissolved in acetone (100 mL), and the solution layeredwith n-hexanes (500 mL), and stored in the freezer. The resultingprecipitate is collected by filtration yield 101.69 g (80%) of Formula Eas a yellow solid. For Formula E: mp 43°-45° C.; FAB MS, (M+H)⁺: m/e493; HRMS, (M+H)⁺; 493; HRMS, (M+H)⁺: 493.2030 (calcd. for C₂₀H₃₃N₂O₁₂,493.2033).

Synthesis of 1,2-diamino-4,5-bis[2-[2-(2-methoxy-ethoxy)ethoxy]ethoxy],Formula F: In an oven dried 500 mL round bottom flask, equipped with aClaisen adapter, pressure equalizing dropping funnel, and refluxcondenser, 1,2-bis[2-[2-2-methoxyethoxy)ethoxy]ethoxy]-4,5dinitrobenzene(Formula E) (20 g, 0.04 mol) is dissolved in absolute ethanol (200 mL).To this clear solution, 10% palladium on carbon (4 g) is added and thedark black suspension is heated to reflux under an argon atmosphere.Hydrazine hydrate (20 mL) in EtOH (20 mL) is added dropwise over 10 minto avoid bumping. The resulting brown suspension is heated at reflux for1.5 h at which time the reaction mixture is colorless and TLC analysis(95/5; CH₂Cl₂/MeOH) displays a low R/UV active spot corresponding to thediamine. Therefore, the mixture is hot filtered through Celite and thepad rinsed with absolute ethanol (50 mL). The solvent is removed underreduced pressure and the resulting light brown oil is dried in vacuo (inthe dark) for 24 h to yield 15.55 g (89%) of1,2-diamino-bis[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]benzene (Formula F).For Formula F: FAB MS,M+: m/e 432; HRMS, M+: 432.2471 (calcd. forC₂₀H₃₆N₂O₈, 432.2482). This material is taken to the next step withoutfurther purification.

Synthesis of4,5-diethyl-10,23-dimethyl-9,24-bis(3-hydroxypropyl)-16,17-bis[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]-13,20,25,26,27-pentaazapentacyclo[20.2.1.1^(3.6).18, 11.0^(14.19)] heptacosa-3,5,8,10,12,14,16,18,20,22,24undecaene,Formula H. In an oven dried 1 L round-bottom flask,2,5-bis[(5-formyl-3(3-hydroxypropyl)4-methyl-pyrrol-2yl)methyl]-3,4-diethylpyrrole(Formula G) (The synthesis of Formula G is provided in U.S. Pat. No.5,252,720, incorporated by reference herein.) (30.94) g, 0.0644 mol) and4,5-diamino-bis[2[2-(2-methoxyethoxy)ethoxy)ethoxy]benzene (formula F)(28.79 g, 0.0644 mol) are combined in absolute methanol (600 mL) underan argon atmosphere. To this well stirred suspension, a mixture ofconcentrated hydrochloric acid (6.7 m:) in absolute methanol 200 mL isadded in one portion. The mixture is gradually heated to 50° C., atwhich time the reaction goes from a cloudy suspension of startingmaterials to a dark red homogeneous solution as the reaction proceeded.After 3 h the reaction is judged complete by TLC analysis and UV/visiblespectroscopy (λ_(max) 369 nm). The reaction mixture is cooled to roomtemperature, 60 g of activated carbon (DARCO™) is added, and theresulting suspension is stirred for 20 min. The dark suspension isfiltered through Celite to remove the carbon, the solvent evaporated todryness, and the crude Formula H dried in vacuo overnight. Formula H isrecrystallized from isopropyl alcohol/n-heptane to afford 50 g (85%) ofa scarlet red solid. For Formula H: ¹H NMR (CD₃OD): δ1.11 (t, 6H,CH₂CH₃), 1.76 (p, 4H, pyrr-CH₂CH₂CH₂OH), 2.36 (s, 6H, pyrr-CH₃), 2.46(q, 4H, CH₂CH₃), 2.64 (t, 4H, pyrr-CH₂CH₂CH₂OH), 3.29 [s, 6H,(CH₂CH₂O)₃CH₃], 3.31 (t, 4H, pyrr-CH₂CH₂CH₂OH), 3.43-3.85 (m, 20H,CH₂CH₂OCH₂CH₂OCH₂CH₂O), 4.0 (s, 4H, (pyrr)₂—CH₂), 4.22 (t, 4H,PhOCH₂CH₂O), 7.45 (s, 2H, PhH), 8.36 (s, 2H, HC═N); UV/vis:[(MeOH)λ_(max) nm]: 369; FAB MS, [M+H]⁺: m/e 878.5; HRMS, [M+H]⁺: m/e878.5274 (calcd. for [C₄₈H₇₂N₅O₁₀]⁺ 878.5279).

Synthesis of the gadolinium (HI) complex of4,5-diethyl-10,23-dimethyl-9,24-bis(3-hydroxypropyl)-16,17-bis[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]pentaazapentacyclo[20.2.1.1^(3.6),1^(8.11),0^(14.19)]heptacosa-1,3,5,7,9,11(27),12,14,16,18,20,22(25),23-tridecaene,Formula I. Formula I is prepared according to the process outlined inFIG. 22. In a dry 2 L three-necked round-bottom flask, Formula H (33.0g, 0.036 mol) and gadolinium(II) acetate tetrahydrate (15.4 g, 0.038mol) are combined in methanol (825 mL). To this well stirred redsolution, gadolinium(III) acetate tetrahydrate (15.4 g, 0.038 mol) andtriethylamine (50 mL) are added and the reaction is heated to reflux.After 1.5 h, air is bubbled (i.e., at reflux) for 4 h into the darkgreen reaction solution with aid of a gas dispersion tube (flow rate=20cm³/min). At this point, the reaction mixture is carefully monitored byUV/Visible spectroscopy (i.e., a spectrum is taken every 0.5-1 h,˜1 dropdiluted in 4-5 mL MeOH). The reaction is deemed complete by UV/Vis (InMeOH ratio: 342 nM/472 nm=0.22-0.24) after 4 h. The dark green reactionis cooled to room temperature, filtered through Celite into a 2 L roundbottom flask, and the solvent removed under reduced pressure. The darkgreen solid is suspended in acetone (1 L) and the resulting slurry isstirred for 1 h at room temperature. The suspension is filtered toremove the red/brown impurities (incomplete oxidation products), thesolids rinsed with acetone (200 mL), and air dried. The crude complex(35 g) is dissolved in MeOH (600 mL), stirred vigorously for 15 min,filtered through Celite, and transferred to a 2 L Erlenmeyer flask. Anadditional 300 mL of MeOH and 90 mL water are added to the flask, alongwith acetic acid washed LZY-54 zeolite (150 g). The suspension isagitated with an overhead mechanical stirrer for approximately 3-4 h.The zeolite extraction is deemed complete with the absence of freeGd(III). [To test for free gadolinium, the crude Formula I is spottedheavily onto a reverse phase TLC plate (Whatman KC8F, 1.5×10 cm) and thechromatogram developed using 10% acetic acid in methanol. The greencomplex moved up the TLC plate close to the solvent front. Any freegadolinium metal will remain at the origin under these conditions. Afterdeveloping the chromatogram, the plate is dried and the lower ¼ of theplate stained with an Arsenazo III solution in methanol (4 mg ArsenazoIII in 10 mL methanol). A very faint blue spot (indicative of freemetal) is observed at the origin against a pink background indicatingvery little free gadolinium metal.] The zeolite is removed through aWhatman #3 filter paper and the collected solids rinsed with MeOH (200mL). The dark green filtrate is loaded onto a column of AmberliteIRA-904 anion exchange resin (30 cm length×2.5 cm diameter) and elutedthrough the resin (ca. 10 mL/min flow rate) into a 2 L round bottomflask with 300 mL 1-butanol. The resin is rinsed with an additional 100mL of MeOH and the combined eluent evaporated to dryness under reducedpressure. The green shiny solid Formula I is dried in vacuo for severalhours at 40° C. to a well stirred ethanoic solution (260 mL of Formula Iat 55°-60° C., n-heptanes (ca. 600 mL) is added dropwise (flow=4 mL/min)from a 1 L pressure-equalizing dropping funnel. During the course of 1.5h (300 mL addition) the green Formula I began to crystallize out of thedark mixture. After complete addition, the green suspension is cooledand stirred for 1 h at room temperature. The suspension is filtered, thesolids rinsed with acetone (250 mL), and dried in vacuo for 24 h toafford 26 g (63%), UV/vis: [(MeOH)λ_(max)nm]: 316, 350, 415, 473, 739;FAB MS, (M-20 Ac)⁺: m/e 1030; HRMS, (M-20 Ac)⁺: m/e 1027.4036 (calcd.for C₄₈H₆₆ ¹⁵⁵GdN₅O₁₀, 1027.4016). Anal. calcd. for [C₅₂H₇₂GdN₅O₁₄]0.5H₂O: C, 53.96: H, 6.36; N, 6.05, Gd, 13.59. Found: C, 53.73; H, 6.26;N, 5.82; Gd, 13.92.

Synthesis of the Lutetium(III) Complex of Formula H: The macrocyclicligand Formula H is oxidatively metalated using lutetium(III) acetatehydrate (9.75 g, 0.0230 mol) and triethylamine (22 mL) in air-saturatedmethanol (1500 mL) at reflux. After completion of the reaction (asjudged by the optical spectrum of the reaction mixture), the deep greensolution is cooled to room temperature, filtered through a pad ofcelite, and the solvent removed under reduced pressure. The dark greensolid is suspended in acetone (600 mL, stirred for 30 min at roomtemperature, and then filtered to wash away the red/brown impurities(incomplete oxidation products and excess triethylamine). The crudecomplex is dissolved into MeOH (300 mL, stirred for −30 min, and thenfiltered through celite into a 1 L Erlenmeyer flask An additional 50 mLof MeOH and 50 mL of water are added to the flask along with acetic acidwashed LZY-54 zeolite (40 g). The resulting mixture is agitated orshaken for 3 h, then filtered to remove the zeolite. The zeolite cake isrinsed with MeOH (100 mL and the rinse solution added to the filtrate.The filtrate is first concentrated to 150 mL and then loaded onto acolumn (30 cm length×2.5 cm diameter) of pretreated Amberlite IRA-904anion exchange resin (resin in the acetate form). The eluent containingthe bis-acetate lutetium(III) texaphyrin complex is collected.concentrated to dryness under reduced pressure, and recrystallized fromanhydrous methanol/t-butylmethyl ether to afford 11.7 g(63%) of a shinygreen solid. For the complex: UV/vis: [(MeOH) λ_(max) nm, (log ε)]:354,414, 474 (5.10), 672, 732; FAB MS, [IM-OAc⁻]⁺: m/e 1106.4; HRMS,(M-OAc³¹ ]⁺: m/e 1106.4330 (calcd. for [C₄₈H₆₆N₅;O₁₀Lu(OAc)]⁺,1106.4351). Anal. calcd. for [C₄₈H₆₆N5O₁₀Lu](OAc)₂H2O; C, 52.74; H,6.30; N, 5.91. Found: C, 52.74; H, 6.18; N, 5.84.

EXAMPLE 2 Synthesis of a T2B1 TXP Metal Complex-Oligonuleotide Conjugate

FIGS 23A-H illustrate the synthesis of a light activated drug conjugate.The light activated drug is a texaphyrin coupled with an oligonucleotidewhich is complementary to a DNA site. As a result, the light activateddrug conjugate can bind the complementary DNA site and will cleave thesite upon activation by ultrasound. (Note: References to “Formula A,”“Formula B,” etc. relate to FIGS. 23A, 23B, etc.)

Synthesis of 4-Amino-1-[1-(ethyloxy)acetyl-2-oxy]-3-nitrobenzene(Formula B of FIG. 19), n=1. Potassium carbonate (14.0 g, 101 mmol) and4-amino-3-nitrophenol (Formula A) (10.0 g, 64.9 mmol) are suspended in150 mL dry acetonitrile. Ethyl-2-iodoacetate (10 mL, 84.5 mmol) (orethyl iodobutyrate may be used, in that case n=3) is added via syringe,and the suspension is stirred at ambient temperature for ca 21 h.Chloroform (ca 375 mL) is added and is used to transfer the suspensionto a separatory funnel, whereupon it is washed with water (2×ca 100 mL).The water washes are in turn washed with CHOl₃ (ca 100 mL) and thecombined CHCl₃ extracts are washed with water (ca 100 mL). Solvents areremoved on a rotary evaporator, and the residue is redissolved in CHCl₃(ca 500 mL) and precipitated into hexanes (1.5 L). After standing twodays, the precipitate is filtered using a coarse fritted funnel anddried in vacuo to provide 14.67 g (Formula B), n=1 (94.1%). TLC:Rf=0.43, CHCl₃.

Synthesis of 4-Amino-1-[1-(hydroxy)acetyl-2-oxy]-3-nitrobenzene (FormulaC), n=1. 4-Amino-1-[1-(ethyloxy)acetyl-2-oxy]-3-nitrobenzene (FormulaB), n=1, (10.00 g, 37.3 mmol) is dissolved in tetrahydrofuran (100 mL),aqueous sodium hydroxide(1M solution, 50 mL) is added and the solutionis stirred at ambient temperature for ca. 21 h. Tetrahydrofuran isremoved on a rotary evaporator, and water (100 mL) is added. Thesolution is washed with CHCl₃ (ca. 200 mL), the neutralized by additionof hydrochloric acid (1M solution, 50 mL). The precipitate which formedis filtered after standing a few minutes washed with water, and dried invacuo to provide 8.913 g compound (Formula C), n=1 (99.5%). TLC:Rf=0.65, 10% methanol/CHCl₃.

Synthesis of16-[1-(Hydroxy)acetyl-2-oxy]-9,24bis(3-hydroxypropyl)4,5-diethyl-10,23-dimethyl-13,20,25,26,27-pentaazapentacyclo[20.2.1.1^(3.6).1^(8.11).0^(14.19)]heptacosa-3,5,8,10,12,14(19),15,17,20,22,24-undecaene (Formula E), n=1:4-Amino-1-[1-(hydroxy)acetyl-2-oxy]-3-nitrobenzene (Formula C), n=1.(1,800 g, 8.49 mmol) is dissolved in methanol (100 mL) in a 1 L flask.Palladium on carbon (10%, 180 mg) is added, and the atmosphere insidethe flask is replaced with hydrogen at ambient pressure. A greyprecipitate is formed after ca 3 h, and the supernatant is clear.Methanol is removed in vacuo, taking precautions to prevent exposure tooxygen, and the compound is dried overnight in vacuo. Isopropyl alcohol(500 mL) and HC1 (12M, 400 μL) are added, and the suspension is allowedto stir for ca. 15′.2,5-Bis[(3-hydroxypropyl-5-formyl-4-methylpyrrol-2-y)methyl]-3,4-diethylpyrrole(Formula D) (n=1) (4.084 g, 8.49 mmol) is added, and the reactionstirred at room temperature under argon for 3 hours. Hydrochloric acidis again added (12M, 400 μL) and the reaction again is allowed to stirfor an additional 3.5 h The resulting red solution is filtered throughcelite, and the filtercake is washed with isopropyl alcohol until thefiltrate is colorless. Solvent is reduced to a volume of ca. 50 mL usinga rotary evaporator, whereupon the solution is precipitated into rapidlystirring Et₂O (ca. 700 mL). Formula E (n=1) is obtained as a red solid(5.550 g, 98.4%) upon filtering and drying in vacuo. TLC: Rf=0.69, 20%methanol/CHCl₃ (streaks, turns green on plate with I₂).

Synthesis of metal complex of16-[1-(hydroxy)acetyl-2-oxy]-9,24-bis(3-hydroxypropyl)-4,5-diethyl-10,23-dimethyl-13,20,25,26,27-pentaazapentacyclo[20.2.1.1^(3.6.).1^(8.11).0^(14.19)]heptacosa-1,3,5,7,9,11(27),12,14(19),15,17,20,22(25),23-tridecaene(Formula F), n=1: Approximately equal molar amounts of the protonatedform of the macrocycle,16-[1-(hydroxy)acetyl-2-oxy]-9,24-bis(3-hydroxypropyl)-4,5-diethyl-10,23-dimethyl-13,20,25,26,27-pentaazapentacyclo[20.2.0.1.1^(3.6.).1^(8.11).0^(14.19)]heptacosa-3,5,8,10,12,14(19),15,17,20,22,24-undecaenehydrochloride (Formula E), n=1, and a metal acetate pentahydrate arecombined with triethylamine in methanol, and are heated to reflux underair for 5.5 h. The reaction is cooled to room temperature, and stored at−20° C., overnight. Solvent is removed on a rotary evaporator, acetoneis added, and the suspension is stirred on a rotary evaporator for 2 h.The suspension is filtered and the precipitate dried briefly in vacuo,whereupon a solution is formed in methanol (ca. 250 mL) and water (25mL). The pH is adjusted to 4.0 using HCl (1M), HCl-washed zeolite LZY54is added (ca. 5 g) and the suspension is stirred on the rotaryevaporator for ca. 6 h. Amberlite™ IRA-900 ion exchange resin (NaFtreated, ca. 5 g) is added, and the suspension is stirred for anadditional hour. The suspension is filtered, the resin is washed withmethanol (ca. 100 mL), and the filtrate is adjusted to pH 4.0 using HCl(1M). Solvents are removed on a rotary evaporator, using ethanol (abs.)to remove traces of water. After drying in vacuo, the compound isdissolved in methanol (25 mL) and precipitated into rapidly stirringEt₂O (300 mL). Formula F, n=1, is obtained as a precipitate afterfiltering and drying in vacuo. An analytical sample is prepared bytreating 50 mg of Formula F, n=1, dissolved in methanol (25 mL) withacetic acid-washed zeolite, then acetic acid-washed Amberlite™ for ca. 1h After reducing methanol to a minimum volume, the solution isprecipitated into rapidly stirring Et₂O (70 mL), filtered, and dried invacuo.

Postsynthetic modification of oligodeoxynucleotide-amine (Formula G)with metal complex (Formula F), n=1: The metal complex of16-[1-(hydroxy)acetyl-2-oxy]-9,24-bis(3-hydroxypropyl)-4,5-diethyl-10,23dimethyl-13,20,25,26,27-pentaazapentacyclo[20.2.1.1^(3.6).1^(8.11).0^(14.19)]heptacosa-1,3,5,7,9,11(27),12,14(19),15,17,20,22(25),23-tridacaene(Formula F), n=1, (about 30 mol) and N-hydroxysuccinimide (43 μmol) aredried together overnight in vacuo. The compounds are dissolved indimethylformamide (anhydrous, 500 μL) and dicyclohexylcarbodiimide (10mg, 48 μmol) is added. The resulting solution is stirred under argonwith protection from light for 8 h, whereupon a 110 μL aliquot is addedto a solution of oligodeoxynucleotide (Formula G) (87 μmol) in a volumeof 350 μL of 0.4M sodium bicarbonate buffer in a 1.6 mL Eppendorf tube.After vortexing briefly, the solution is allowed to stand for 23 h withlight protection. The suspension is filtered through 0.45 μm nylonmicrofilterfuge tubes, and the Eppendorf tube is washed with 250 μLsterile water. The combined filtrates are divided into two Eppendorftubes, and glycogen (20 mg/mL, 2 μL) and sodium acetate (3M, pH 5.4 30μL) are added to each tube. After vortexing, ethanol (absolute, 1 mL) isadded to each tube to precipitate the DNA. Ethanol is decanted followingcentrifugation, and the DNA is washed with an additional 1 mL aliquot ofethanol and allowed to air dry. The pellet is dissolved in 50% formamidegel loading buffer (20 μL), denatured at 90° C. for ca. 2′, and loadedon a 20% denaturing polyacrylamide gel. The band corresponding toconjugate (Formula H), n=1, is cut from the gel, crushed and soaked in1×TBE buffer (ca. 7 mL) for 1-2 days. The suspension is filtered throughnylon filters (0.45 μm) and desalted using a Sep-pak™ reverse phasecartridge. The conjugate is eluted from the cartridge using 40%acetonitrile, lyophilized overnight, and dissolved in 1 mM HEPES buffer,pH 7.0 (500 μL). The solution concentration is determined using UV/visspectroscopy.

EXAMPLE 3 Synthesis of Texaphyrin Metal Complexes with Amine-, Thiol- orHydroxy-linked Oligonucleotides

Amides, ethers, and thioethers are representative of linkages which maybe used for coupling site-directing molecules such as oligonucleotidesto light activated drugs such as texaphyrin metal complexes asillustrated in FIGS. 24A-F. (Note: References to “Formula A,” “Formulab,” etc. relate to FIGS. 24A, 24B, etc.) Oligonucleotides or othersite-directing molecules functionalized with amines at the 5′-end, the3′-end, or internally at sugar or base residues are modifiedpost-synthetically with an activated carboxylic ester derivative of thetexaphyrin complex. In the presence of a Lewis acid such as FeBr₃, abromide derivatized texaphyrin (for example, Formula C of FIG. 24) willreact with an hydroxyl group of an oligonucleotide to form and etherlinkage between the texaphyrin linker and the oligonucleotide.Alternatively, oligonucleotide analogues containing one or morethiophosphate or thiol groups are selectively alkylated at the sulfuratom(s) with an alkyl halide derivative of the texaphyrin complex.Oligodeoxynucleotide-complex conjugates are designed so as to provideoptimal catalytic interaction between the targeted DNA phosphodiesterbackbone and the texaphyrino.

Oligonucleotides are used to bind selectively compounds which includethe complementary nucleotide or oligo- or polynucleotides containingsubstantially complementary sequences. As used herein, a substantiallycomplementary sequence is one in which the nucleotides generally basepair with the complementary nucleotide and in which there are very fewbase pair mismatches. The oligonucleotide may be large enough to bindprobably at least 9 nucleotides of complementary nucleic acid.

For general reviews of synthesis of DNA, RNA, and their analogues, seeOligonucleotides and Analogues, F. Eckstein, Ed., 1991. IRL Press, NewYork; Oligonucleotide Synthesis, M. J. Gait, Ed., 1984, IRL PressOxford, England; Caracciolo et al. (1989); Bioconjugate Chemistry,Goodchild, J. (1990); or for phosphonate synthesis, Matteucci, Md. etal., Nucleic Acids Res. 14:5399 (1986) (these references areincorporated by reference herein).

In general, there are three commonly used solid phase-based approachesto the synthesis of oligonucleotides containing conventional 5′-3′linkages. These are the phosphoramidite method, the phosphonate method,and the triester method.

A brief description of a current method used commercially to synthesizeoligomeric DNA is as follows: Oligomers up to ca. 100 residues in lengthare prepared on a commercial synthesizer, eg., Applied Biosystems Inc.(ABI) model 392, that uses phosphoramidite chemistry. DNA is synthesizedfrom the 3′ to the 5′ direction through the sequential addition ofhighly reactive phosphorous(III) reagents called phosphoramidites. Theinitial 3′ residue is covalently attached to a controlled porositysilica solid support, which greatly facilitates manipulation of thepolymer. After each residue is coupled to the growing polymer chain, thephosphorus(III) is oxidized to the more stable phosphorus(V) state by ashort treatment with iodine solution. Unreacted residues are capped withacetic anhydride, the 5′-protective group is removed with weak acid, andthe cycle may be repeated to add a further residue until the desired DNApolymer is synthesized. The full length polymer is released from thesolid support, with concomitant removal of remaining protective groups,by exposure to base. A common protocol uses saturated ethanolic ammonia

The phosphonate based synthesis is conducted by the reaction of asuitably protected nucleotide containing a phosphonate moiety at aposition to be coupled with a solid phase-derivatized nucleotide chainhaving a free hydroxyl phosphonate ester linkage, which is stable toacid. Thus, the oxidation to the phosphate or thiophosphate can beconducted at any point during synthesis of the oligonucleotide or aftersynthesis of the oligonucleotide is complete. The phosphonates can alsobe converted to phosphoramidate derivatives by reaction with a primaryor secondary amine in the presence of carbon tetrachloride.

In the triester synthesis, a protected phosphodiester nucleotide iscondensed with the free hydroxyl of a growing nucleotide chainderivatized to a solid support in the presence of coupling agent. Thereaction yields a protected phosphate linkage which may be treated withan oximate solution to form unprotected oligonucleotide.

To indicate the three approaches generically, the incoming nucleotide isregarded as having an “activated” phosphite/phosphate group. In additionto employing commonly used solid phase synthesis techniques,oligonucleotides may also be synthesized using solution phase methodssuch as diester synthesis. The methods are workable, but in general,less efficient for oligonucleotides of any substantial length.

Preferred oligonucleotides resistant to in vivo hydrolysis may contain aphosphorothioate substitution at each base (J. Org. Chem. 55:4693-469,(1990) and Agrawal, (1990)). Oligodeoxynucleotides or theirphosphorothioate analogues may be synthesized using an Applied Biosystem380B DNA synthesizer (Applied Biosystems, Inc., Foster City, Calif.).

EXAMPLE 4 Synthesis of Diformyl Monoacid Tripyrrane (FIG. 25C, FormulaH) and Oligonucleotide Conjugate (FIG. 25D, Formula J)

The present example provides for the synthesis of a light activated drugconjugate. The light activated drug conjugate includes a oligonucleotideacting as a site directing molecule coupled with the tripyrrane portionof a texaphyrin as illustrated in FIGS. 25A-J. (Note: References to“Formula A,” “Formula b,” etc. relate to FIGS. 25A, 25B, etc.)

Synthesis of Dimethylester Dibenzylester Dipyrromethane (Formula B): Athree-neck 1000 mL round-bottom flask set with a magnetic stirring bar,a thermometer, a heating mantle, and a reflux condenser attached to anargon line is charged with methylester acetoxypyrrole (Formula A)(100.00 g; 267.8 mmol), 200 proof ethyl alcohol (580 mL), and deionizedwater (30 mL.) The reaction mixture is heated up and when the resultingsolution begins to reflux, 12N aq. hydrochloric acid (22 mL) is addedall at once. The flask contents are stirred under reflux for two hours.The heating element is replaced by a 0° C. bath and the resulting thickmixture is stirred for two hours prior to placing it in the freezerovernight.

The mixture is filtered over medium fritted glass funnel, pressed with arubber dam, and washed with hexanes until the filtrate comes outcolorless. The collected solids are set for overnight high vacuum dryingat 30° C. to afford slightly yellowish solids (65.85 g, 214.3 mmol,80.0% yield.)

Synthesis of Dimethylester Diacid Dipyrromethane, Formula C: All theglassware is oven dried. A three-neck 2000 mL round-bottom flask setwith a magnetic stirring bar, a hydrogen line, and a vacuum line ischarged with dimethylester dibenzylester dipyrromethane (Formula B)(33.07 g, 53.80 mmol), anhydrous tetrahydrofuran (1500 mL), and 10%palladium on charcoal (3.15 g.) The flask is filled with dry hydrogengas after each of several purges of the flask atmosphere prior tostirring the reaction suspension under a hydrogen atmosphere for 24hours.

The solvent of the reaction suspension is removed under reducedpressure. The resulting solids are dried under high vacuum overnight.

The dry solids are suspended in a mixture of saturated aqueous sodiumbicarbonate (1500 mL) and ethyl alcohol (200 mL), and stirred at itsboiling point for five minutes. The hot suspension is filtered overcelite. The filtrate is cooled down to room temperature and acidified topH 6 with 12N aqueous hydrochloric acid. The resulting mixture isfiltered over medium fritted glass. The collected solids are dried underhigh vacuum to constant weight (21.63 g, 49.78 mmol, 92.5% yield.)

Synthesis of Methylester Dibenzylester Tripyrrane, Formula E: Athree-neck 2000 mL round-bottom flask set with a heating mantle, amagnetic stirring bar, a thermometer, and a reflux condenser attached toan argon line is charged with dimethylester diacid dipyrromethane(Formula C) (21.00 g, 48.33 mmol), ethyl acetoxy pyrrole (Formula D)(30.50 g), p-toluenesulfonic acid monohydrate (1.94 g), trifluoroaceticacid (39 mL), and methyl alcohol (1350 mL.) The flask contents areheated and stirred under reflux for two hours. The heating element isreplaced with a 0° C. bath and the stirring is continued for half anhour prior to placing the resulting mixture in a freezer overnight.

The cold mixture is filtered over medium fritted glass. The collectedsolids are washed with hexanes and dried under high vacuum overnight(13.05 g, 19.25 mmol, 39.85 yield).

Synthesis of Methylester Diacid Tripyrrane, Formula F: All the glasswareis oven dried. A three-neck 500 mL round-bottom flask set with amagnetic stirring bar, a hydrogen line, and a vacuum line is chargedwith methylester dibenzylester tripyrrane (Formula E) (12.97 g, 19.13mmol), anhydrous tetrahydrofuran (365 mL), and 10% palladium on charcoal(1.13 g.) The flask is filled with dry hydrogen gas after each ofseveral purges of the flask atmosphere prior to stirring the reactionsuspension for 24 hours under a hydrogen atmosphere at room temperature.

The reaction suspension is filtered over celite. The solvent of thefiltrate is removed under reduced pressure to obtain a foam which isdried under high vacuum overnight (10.94 g, 21.99 mmol, 87.0% pure.)

Synthesis of Monoacid Tripyrrane, Formula H: All the glassware is ovendried. A three-neck 500 mL round-bottom flask set with a mechanicalstirrer, a thermometer, a 0° C. bath, and an additional funnel set withan argon line is charged with methylester diacid tripyrrane (Formula F)(10.20 g, 17.83 mmol). Trifluoroacetic acid (32.5 mL) is dripped intothe reaction flask from the addition funnel over a 45 minute periodkeeping the flask contents below 5° C. The resulting reaction solutionis stirred at 0° C. for 15 minutes, and then at 20° C. for three hours.Triethylorthoformate (32.5 mL) is dripped into the flask from theaddition funnel over a 20 minute period keeping the flask contents below−25° C. by means of a dry ice/ethylene glycol bath. The reactionsolution is stirred for one hour at −25 ° C. and then a 0° C. bath isset up. Deionized water (32.5 mL) is dripped into the reaction flaskfrom the addition funnel keeping the flask contents below 10° C. Theresulting two phase mixture is stirred at room temperature for 75minutes and then added 1-butanol (200 mL.) The solvents are removedunder reduced pressure. The resulting dark oil is dried under highvacuum overnight to obtain black solids (11.64 g.)

A three-neck 2000 mL round-bottom flask set with a thermometer, aheating mantle, a magnetic stirring bar, and a reflux condenser attachedto an argon line, is charged with the crude methylester diformyltripyrrane (Formula G) (11.64 g), methyl alcohol (900 mL), deionizedwater (60 mL), and lithium hydroxide monohydrate (4.7 g.) The flaskcontents are heated, stirred under reflux for two hours, cooled down toroom temperature, added deionized water (250 mL), acidified with 12N aq.HCl to pH 5, and then stirred at 0° C. for one hour. The resultingmixture is filtered over medium fritted glass funnel. The collectedsolids are dried under high vacuum to constant weight prior to theirpurification by column chromatography (silica gel, MeOH in CH₂Cl₂,0-10%; 3.64 g, 8.06 mmol, 45.2% yield.)

The monoacid tripyrrane (Formula H) is condensed with a derivatizedortho-phenylene diamine to form a nonaromatic precursor which is thenoxidized to an aromatic metal complex, for example, Formula I. Anoligonucleotide amine may be reacted with the carboxylic acidderivatized texaphyrin Formula I to form the conjugate Formula J havingthe site-directing molecule on the T (tripyrrane) portion of themolecule rather than the B (benzene) portion.

EXAMPLE 5

The following example describes the synthesis of an emulsion includingtin ethyl etiopurpurin (SnEt₂) which is illustrated in FIG. 26.

Several emulsions are prepared as described above. In 5 ml glass tubes,medium chain length oil known as MCT oil (Miglyol 801, Hüls America,Piscataway, N.J.) is combined with 10 mg/gm SnEt₂ plus excipients asdescribed above. Certain emulsions also included additional excipientsin the following concentrations: ethanol at mg/gm oil; egg phospholipidsat 75 mg/gm oil; and sodium cholate at 10 mg/gm oil. After incubatingfor 30 minutes at 55° C., the tubes stand overnight at room temperature(19°-22° C.). The tubes arc centrifuged to remove bulk precipitates, andsupernatants are filtered through 0.45 μm nylon membrane to remove anyundissolved drug. Aliquots of filtrate are then diluted inchloroform:isopropyl alcohol (1:1) for spectrophotometric determinationof drug concentration (absorbance at 662 nm). Reference standards areprepared with known concentrations of SnEt₂ in the same solvent.

The concentration of SnEt₂ in each of the emulsions is illustrated inTable 2. As illustrated, the concentration of SnEt₂ in the emulsion canbe more than ten times the concentration in MCT oil alone.

TABLE 2 Drug Solubility in Oil SnEt₂ SnEt₂ Excipient CombinationConcentration Concentration Added to MCT Oil mg/gm oil Normalized MCToil alone 0.38 1.00 + ethanol 0.28 0.74 + egg phospholipids (EYP) 0.892.34 + Na cholate 1.17 3.08 + ethanol + EYP 1.37 3.61 + EYP + Na cholate1.77 4.66 + ethanol + Na cholate 2.20 5.79 + ethanol + EYP + Na cholate4.92 12.95

EXAMPLE 6

This example illustrates relative efficiencies of several bile salts.Mixtures of MCT oil, egg phospholipids, ethanol, and SnEt₂ are incubatedwith different bile salts, all at 4.6 mM¹, under the same conditionsdescribed above. As shown in Table 3, sodium cholate is the mostefficient solubilizer. Cholic acid lacks solubilizing action in the oil.

TABLE 3 Sodium Cholate is the Most Efficient Co-Solubilizer for SnEt₂SnEt₂ SnEt₂ Concentration Concentration Bile compound mg/gm oilNormalized None 1.26 1.00 Na Tauracholate 1.13 0.90 Cholic acid 1.331.06 Na glycocholate 2.22 1.76 Na deoxycholate 2.31 1.83 Na cholate 3.702.94 equivalent to sodium cholate addition at 10 mg per gram oil or 0.2%w/v in a 20% o/w emulsion equivalent to sodium cholate addition at 10 mgper gram oil or 0.2% w/v in a 20% o/w emulsion

EXAMPLE 7

The following Example illustrates the preparation of liposomes includingBPD-MA (See FIG. 17);as alight activated drug. A 100-ml batch of BPD-MAliposomes is prepared at room temperature (about 20° C.) using thefollowing general procedure. BPD-MA, butylated hydroxytoluene (“BHT”),ascorbyl palmirate, and the phospholipids DMPC and EPG are dissolved inmethylene chloride. The molar ratio of light activated drug: EPG:DMPC is1.0:3.7 and has the compositions illustrated in Table 4.

TABLE 4 Light activated drug 0.21 g EPG 0.68 g DMPC 1.38 g BHT 0.0002 gAscorbic acid 6-palmitate 0.002 g Lactose NF 10 g crystaliine injectableWater for injection 100 ml

Using the above formulation, the total lipid concentration (% w/v) isabout 2.06. The resulting solution is filtered through a 0.22 μm filterand then dried under vacuum using a rotary evaporator. Drying iscontinued until the amount of methylene chloride in the solid residue isno longer detectable by gas chromatography.

A 10% lactose/water-for-injection solution is then prepared and filteredthrough a 0.22 μm filter. Instead of being warmed to a temperature ofabout 35° C., the lactose/water solution is allowed to remain at roomtemperature (about 25° C.) for addition to the flask containing thesolid residue of the light activated drug/phospholipid. The solidresidue is dispersed in the 10% lactose/water solution at roomtemperature, stirred for about one hour, and passed through aMicrofluidizer™ homogenizer three to four times with the outlettemperature controlled to about 200°-250° C. The solution is thenfiltered through a 0.22 μm Durapore, hydrophilic filter.

The filterability of the composition in g/cm² is typically greater thanabout 10. Moreover, the yield is about 100% by HPLC analysis, with lightactivated drug potency typically being maintained even after sterilefiltration. Average particle sizes vary from about 150 to about 300 nm(±50 nm).

EXAMPLE 8

The following Example describes the delivery of a light activated drugto an atheroma. An emulsion is prepared having about 0.6 g SnEt₂/ml ofemulsion and about 20 g of MCT oil based hydrophobic phase/ml ofemulsion. The catheter illustrated in FIG. 7C is positioned in a vesselof the cardiovascular system using over the guidewire techniques. Thecatheter is positioned such that the media delivery port is adjacent tothe atheroma using radiopaque markers on the catheter and the balloon isexpanded into contact with the vessel wall. The emulsion is deliveredvia the third utility lumen 16B of the catheter 10. After the deliveryof the emulsion, the ultrasound energy is delivered at about 0.3 W/cm²at a frequency of approximately 1.3 MHz for about ten minutes. After thedelivery of ultrasound energy has concluded, the catheter is withdrawnfrom the vasculature of the tumor.

EXAMPLE 9

The following Example describes the delivery of a light activated drugto a tumor. An emulsion is prepared having approximately 0.8 g SnEt₂/mlof emulsion and approximately 30 g of MCT oil based hydrophobic phase/mlof emulsion. The catheter 10 illustrated in FIG. 3A is positioned in thevasculature of a tumor using over the guidewire techniques. The catheteris positioned such that the media delivery port is within the tumorusing radiopaque markers included on the catheter. The prepared emulsionis delivered into the vasculature of the tumor via the utility lumen16A. After the delivery of the emulsion, the ultrasound energy isdelivered at about 0.3 W/cm² at a frequency of approximately 1.3 MHz forabout fifteen minutes. After the delivery of ultrasound energy hasconcluded, the catheter is withdrawn from the vascular system of thepatient.

EXAMPLE 10

The following Example describes the delivery of a light activated drugto a potential restenosis site. An emulsion is prepared havingapproximately 0.6 g SnEt₂/ml of emulsion and approximately 30 g of MCToil based hydrophobic phase/ml of emulsion. The catheter illustrated inFIG. 7C is positioned in the vasculature of a patient using over theguidewire techniques. The catheter is positioned such that the mediadelivery port is adjacent to a portion of the vessel which waspreviously treated with balloon angioplasty and the balloon is expandedinto contact with the vessel wall. The prepared emulsion is deliveredinto the vasculature of the patient via the third utility lumen 16B.Ultrasound energy is delivered from the ultrasound assembly to thepotential restenosis site at about 0.3 W/cm² at a frequency ofapproximately 1.3 MHz for about ten minutes. After the delivery ofultrasound energy has concluded, the catheter is withdrawn from thevascular system of the patient.

EXAMPLE 11

The following Example describes the delivery of a light activated drugto an atheroma Liposomes are prepared including BPD-MA (See FIG. 17) asthe light activated drug and DMPC and EPG as the phospholipids. Themolar ratio of BPD-MA:EPG:DMPC is about 1:3:7. The catheter illustratedin FIG. 7C is positioned in a vessel of the cardiovascular system usingover the guidewire techniques. The catheter is positioned such that themedia delivery port is adjacent to the atheroma using radiopaque markersincluded on the catheter and the balloon is expanded into contact withthe vessel. Ultrasound energy is delivered at about 0.3 W/cm² at afrequency of approximately 1.3 MHz for about 20 minutes in order torupture the liposomes and cause tissue death within the atheroma. Afterthe delivery of ultrasound energy has concluded, the catheter iswithdrawn from the vascular system of the patient.

EXAMPLE 12

The following Example describes the delivery of a light activated drugto a tumor. Liposomes are prepared including BPD-MA (See FIG. 17) as thelight activated drug and DMPC and EPG as the phospholipids. The molarratio of BPD-MA:EPG:DMPC is about 1:3:7. The catheter illustrated inFIG. 8 is positioned in the vasculature of a tumor using over theguidewire techniques. The catheter is positioned such that the mediadelivery port is within the tumor using radiopaque markers included onthe catheter. Ultrasound energy is delivered at about 0.3 W/cm² at afrequency of approximately 1.3 MHz for about 20 minutes in order torupture the liposomes and cause tissue death within the atheroma Afterthe delivery of ultrasound energy is concluded, the catheter iswithdrawn from the vasculature of the tumor.

EXAMPLE 13

The following Example describes the delivery of a light activated drugto a potential restenosis site. Liposomes are prepared including BPD-MA(See FIG. 17) as the light activated drug and DMPC and EPG as thephospholipids. The molar ratio of BPD-MA:EPG:DMPC is approximately1:3:7. The catheter illustrated in FIG. 7C is positioned in thevasculature of a patient using over the guidewire techniques. Thecatheter is positioned such that the media delivery port is adjacent toa portion of the vasculature which was previously treated with balloonangioplasty and the balloon is inflated into contact with the vesselwall. Ultrasound energy is delivered at about 0.3 W/cm² at a frequencyof approximately 1.3 MHz for about 15 minutes in order to rupture theliposomes and cause tissue death within the atheroma. After the deliveryof ultrasound energy is concluded, the catheter is withdrawn from thevasculature of the patient.

EXAMPLE 14

The following Example describes the delivery of a light activated drugto an atheroma. Liposomes are prepared including BPD-MA (See FIG. 17) asthe light activated drug and DMPC and EPG as the phospholipids. Themolar ratio of BPD-5 MA:EPG:DMPC is about 1:3:7. The phospholipids aresystemically delivered. The catheter illustrated in FIG. 7C ispositioned in the vasculature of a patient using over the guidewiretechniques. The catheter is positioned such that the media delivery portis adjacent to the atheroma and the balloon is inflated into contactwith the vessel wall. Ultrasound energy is delivered at about 0.3 W/cm²at a frequency of approximately 1.3 MHz for about 15 minutes. After thedelivery of ultrasound energy is concluded, the catheter is withdrawnfrom the vasculature of the patient.

EXAMPLE 14

The following Example describes the delivery of a light activated drugto a tumor. Microbubbles are prepared including cisplatin and photofrinaccording to the methods disclosed in U.S. Pat. No. 5,770,222. Themicrobubbles are systemically administered. The catheter illustrated inFIG. 1A is positioned within the vasculature of a tumor. Ultrasoundenergy is delivered at about 0.3 W/cm² at a frequency of approximately1.3 MHz for about 15 minutes. After the delivery of ultrasound energy isconcluded, the catheter is withdrawn from the vasculature of thepatient.

EXAMPLE 14

The following Example describes the delivery of a light activated drugto a tumor. Microbubbles are prepared including cisplatin and photofrinaccording to the methods disclosed in U.S. Pat. No. 5,770,222. Thecatheter illustrated in FIG. 3A is positioned within the vasculature ofa tumor. The microbubbles are delivered to the tumor via the secondutility lumen 16A of the catheter. Ultrasound energy is delivered atabout 0.3 W/cm² at a frequency of approximately 1.3 MHz for about 15minutes. After the delivery of ultrasound energy is concluded, thecatheter is withdrawn from the vasculature of the patient.

EXAMPLE 16

The following Example describes the delivery of a light activated drugto a thrombosis. Microbubbles are prepared including heparin, photofrinand an albumin substrate. The microbubbles are systemicallyadministered. The catheter illustrated in FIG. 1A is positioned adjacentto the thrombosis. Ultrasound energy is delivered at about 0.2 W/cm² ata frequency of approximately 1.3 MHz for about 20 minutes. After thedelivery of ultrasound energy is concluded, the catheter is withdrawnfrom the vasculature of the patient.

What is claimed is:
 1. A method for treating a subdermal tissue site,comprising: providing a catheter for locally delivering a lightactivated drug to the subdermal tissue site, the catheter including anultrasound transducer; placing the catheter into the body near thetissue site; locally delivering the light activated drug to the tissuesite; producing ultrasound energy from the ultrasound transducer; anddirecting the ultrasound energy to the subdermal tissue site followingdelivery of the light activated drug to the subdermal tissue site toactivate at least a portion of the light activated drug.
 2. The methodof claim 1, further comprising directing ultrasound energy to the tissuesite to enhance absorption of the light activated drug into the tissuesite prior to activation of the light activated drug.
 3. The method ofclaim 1, wherein directing the ultrasound energy to the subdermal tissuesite includes positioning the ultrasound transducer adjacent thesubdermal tissue site.
 4. The method of claim 1, wherein the tissue siteis selected from a group consisting of an atheroma and a tumor.
 5. Themethod of claim 1, wherein locally delivering the light activated drugincludes positioning a media delivery port included on the catheteradjacent the tissue site and delivering the media through the media portvia the lumen in a catheter.
 6. The method of claim 1, wherein locallydelivering the light activated drug includes locally delivering a mediawith microbubbles.
 7. The method of claim 6, wherein the microbubblesare liposomes.
 8. The method of claim 1, wherein locally delivering thelight activated drug includes locally delivering an emulsion with alipoid as a hydrophobic phase dispersed in a hydrophylic phase.
 9. Themethod of claim 1, wherein locally delivering the light activated drugincludes locally delivering a site directing molecule coupled with thelight activated drug, the site directing molecule having an affinity foran element of the tissue site.
 10. The method of claim 9, wherein thesite directing molecule is an oligonucleotide.
 11. The method of claim1, wherein the light activated drug is selected from the groupconsisting of GdT2BET, LuT2BET, SnEt₂ and T2B1 TXP MetalComplex-Oligonucleotide Conjugate.
 12. The method of claim 1, whereinthe light activated drug is selected from the group includingphotoreactive pyrrole-derived macrocycles and expanded pyrrole-basedmacrocycles.
 13. The method of claim 1, wherein the light activated drugis selected from the group consisting of porphyrins, chlorins,bacteriochlorins, isobateriochlorins, phthalocyanines, naphtalocyanines,porphycenes, sapphyrins, texaphyrins, derivatives of porphyrins,derivatives of chlorins, derivatives of bacteriochlorins, derivatives ofisobateriochlorins, derivatives of phthalocyanines, derivatives ofnaphtalocyanines, derivatives of porphycenes, derivatives of sapphyrinsand derivatives of texaphyrins.
 14. The method of claim 1, wherein thelight activated drug includes a green porphyrin.
 15. A method foractivating a light activated drug, comprising: providing a catheterincluding an ultrasound transducer; placing the catheter into the bodynear the tissue site; introducing the light activated drug into apatient's body, wherein a subdermal tissue site absorbs at least aportion of the light activated drug; producing ultrasound energy;directing the ultrasound energy from said ultrasound transducer to thesubdermal tissue site including the light activated drug; and activatingat least a portion of the light activated drug in the subdermal selectedtissue site.
 16. The method of claim 15, wherein the ultrasoundtransducer is positioned to direct ultrasound energy into a wall of ablood vessel.
 17. The method of claim 15, wherein a distal portion ofthe catheter is positioned in a patient's circulatory system.
 18. Themethod of claim 15, wherein a distal portion of the catheter ispositioned in a patient's blood vessel.
 19. The method of claim 15,wherein the transducer is positioned to direct ultrasound energy in alateral direction relative to a longitudinal axis of the catheter. 20.The method of claim 15, wherein the ultrasound transducer is positionedin an interior of the patient's body.
 21. The method of claim 15,wherein the ultrasound transducer is positioned in an interior of ablood vessel.
 22. The method of claim 15, wherein the ultrasoundtransducer is positioned adjacent to an atheroma.
 23. The method ofclaim 15, wherein the ultrasound transducer is positioned adjacent to atumor.
 24. The method of claim 15, further comprising providing atemperature sensor on the catheter and measuring a temperature adjacentto the ultrasound transducer for adjusting a level of the ultrasoundenergy in response to the temperature.
 25. A method for preventingrestenosis, comprising: providing an elongate catheter having a drugdelivery lumen and an ultrasound transducer mounted along a distal endportion; advancing the catheter through a patient's vasculature suchthat the distal end portion is located along a treatment site in a bloodvessel; locally delivering an emulsion containing a light activated drugthrough the drug delivery lumen to the treatment site; and directingultrasound energy from said ultrasound transducer along the treatmentsite to activate at least a portion of the light activated drug.
 26. Themethod of claim 25, wherein the emulsion containing a light activateddrug further comprises a plurality of microbubbles.
 27. The method ofclaim 25, wherein the ultrasound energy is directed along the treatmentsite at about 0.3 W/cm² at a frequency of about 1.3 MHz for about 10minutes.
 28. The method of claim 25, further comprising providing atemperature sensor along the distal end portion of the catheter andmeasuring a temperature adjacent to the ultrasound transducer foradjusting a level of the ultrasound energy in response to thetemperature.